Slow Cooker Vegetarian Split Pea Soup with Grilled Cheese Croutons

So this pot of green comfort sort of started by accident

I threw this Slow Cooker Vegetarian Split Pea Soup with Grilled Cheese Croutons together on a rainy Tuesday when the fridge looked like it was auditioning for a minimalist show. A bag of split peas, an onion doing its best, and bread that was a day past perky. Seven hours later the house smelled like a hug, and I cut up a gooey grilled cheese into little crunchy golden squares which, frankly, my family now expects like clockwork. I tried to serve it once without the croutons; mutiny. Also, confession time, I watched a video on carving wooden spoons while this simmered and briefly believed I could whittle one myself. I cannot.

Anyway. This soup is the kind of bowl you eat when you want dinner to cook itself and still feel like you did something clever.

Why you might fall for this bowl of green cozy

• I make this when I need dinner to behave. Toss it in the slow cooker before work and come home to soup that tastes like it had a thoughtful afternoon.
• My kid goes wild for the grilled cheese croutons. Same soup, but the croutons make it feel like a party. Adults are not immune either.
• It uses pantry bits. If you have split peas, an onion, a carrot, and broth, you are 90 percent there.
• I used to be annoyed when split pea soup got too thick. Now I just keep a kettle handy and splash in hot water at the end. Problem solved, no drama.
• Actually, I find it works better if you season twice, a little early and a little later, even though some folks say wait to add salt. On second thought, just taste and go by your stew sense.
• It freezes nicely. Probably better the next day, though honestly I think it is best on day two when everything gets friendly.

What you need, plus swaps I really use

• 2 cups green split peas, rinsed and picked over. Yellow peas work fine if that is what you have.
• 1 large onion, chopped. I sometimes use two shallots instead when I am in a hurry.
• 2 carrots, diced small. Frozen mixed veg will do in a pinch, my grandmother always insisted on fresh carrots, but honestly any version works fine.
• 2 ribs celery, diced.
• 3 cloves garlic, minced. Garlic powder is okay, about a teaspoon.
• 1 bay leaf.
• 1 teaspoon dried thyme or a small handful of fresh if you have it.
• 1 teaspoon smoked paprika, optional but lovely for depth.
• 6 cups vegetable broth, low sodium if possible. Water works with a bouillon cube, I have done it many times.
• 1 medium potato, peeled and cubed, optional for extra body.
• 1 tablespoon olive oil or a knob of butter for a quick sauté. You can skip this if you are truly rushing.
• Salt and black pepper to taste. Start modest, adjust later.
• A splash of apple cider vinegar or lemon juice at the end to brighten.

For the grilled cheese croutons

• 4 slices sturdy sandwich bread, sourdough or country loaf is ace. Day old is perfect.
• 1 to 1 and a half cups shredded sharp cheddar or your favorite melty cheese. I like a mix of cheddar and a bit of Monterey Jack.
• Soft butter for the bread. Mayo works too, yes really.
• Optional schmear inside the sandwich: a dab of Dijon or a tiny smear of garlic paste.

Vegan friends: use olive oil in the soup and your favorite plant based cheese for the croutons, or do garlicky olive oil toast cubes instead.

How it comes together in real life

1. Quick flavor boost, if you have two minutes Warm the olive oil or butter in a skillet and sauté the onion, carrot, and celery with a pinch of salt for 3 to 4 minutes until they smell sweet. If you are racing the clock, just toss them in raw, it still works.
2. Load the slow cooker Rinsed split peas go in, then the veg, garlic, bay leaf, thyme, smoked paprika, broth, and the potato if using. Give it a stir. It will look a bit swampy at this stage, do not worry, it always does.
3. Cook Cover and cook on low for 7 to 8 hours or on high for about 4 to 5. Peas should be tender and mostly fallen apart when you stir.
4. Season and adjust Fish out the bay leaf. Stir in salt and pepper, then a splash of vinegar or lemon. If it is too thick, add hot water until it looks right for you. This is where I usually sneak a taste, okay two.
5. Blend or not I like it mostly rustic. A few pulses with an immersion blender makes it silky but still pebbly. No blender? Mash a few scoops with a potato masher or even the back of a ladle. Or do nothing, it is your bowl.
6. Make the grilled cheese Butter the outside of the bread. Pile cheese inside, maybe a tiny swipe of Dijon. Cook in a medium skillet over medium heat until deeply golden and melty, about 3 to 4 minutes per side. Let rest a minute, then cut into chunky croutons, about bite size squares. Try not to eat all of them while standing over the cutting board, which I have absolutely not done, except I have.
7. Serve Ladle soup into bowls, top with a handful of the grilled cheese croutons. A crack of black pepper, a drizzle of olive oil, maybe some chopped parsley if you want it to look fancy.

Notes I learned the slightly messy way

• Peas sometimes take longer if they are old. If yours are stubborn after the suggested time, add a cup of very hot water, give a stir, and keep it going for another 30 to 45 minutes.
• Salt timing is not scary. I used to hold back until the end, but adding a small pinch early makes the veg taste like themselves. Finish with more to taste.
• A little acid lifts everything. Vinegar or lemon right at the end makes the flavors pop. If it tastes flat, it is not more salt, it is probably a squeeze of lemon.
• If you like a smoky vibe without meat, a pinch more smoked paprika or a tiny drop of liquid smoke does the trick. Go easy, it is bossy.

Variations I tried, including one oddball

• Coconut and lime Stir in half a can of coconut milk and finish with lime. Sounds odd, tastes bright and cozy at the same time.
• Herb garden Add a handful of chopped dill and parsley at the end. Lovely with feta crumbles instead of cheddar croutons.
• Curried version A teaspoon of curry powder and a pinch of cumin went in once and I really liked it. Serve with warm naan toast squares if you are feeling fancy.
• The one that did not work I tried adding zucchini near the beginning. It turned watery and sad. If you want zucchini, add diced pieces for the last 30 minutes only, or skip it.

Gear I use, but you do you

• Slow cooker, 4 to 6 quart. If yours runs hot, start on low and check early.
• Immersion blender. I call it essential, except when I do not bother and just mash with a ladle. A fork even works in a pinch, bit of a workout though.
• Skillet for the grilled cheese. No skillet? Use a sheet pan in a hot oven and flip once, comes out great.
• Cutting board and a decent knife. Nothing fancy.

How to stash leftovers

Let the soup cool until it is just warm, then refrigerate in sealed containers for up to 4 days. It will thicken a lot, add water or broth when reheating. It freezes up to 3 months in portion cups, and thaws nicely in the fridge overnight. Though honestly, in my house it never lasts more than a day.

For freezing basics, this guide from The Kitchn is super helpful and clear.

What to serve alongside, if you fancy

• Extra croutons. I sometimes make a second grilled cheese just for snacking, no shame.
• A crisp green salad with lemony dressing and shaved parm, the fresh bite plays so nicely with the creamy soup.
• Hot sauce on the table. A few drops wake up the bowl.

Pro tips, learned the slightly hard way

• I once tried rushing the sauté and threw raw onions straight in without any fat. It was fine, but the soup tasted flatter, so if you have two minutes, give them a little sizzle.
• Do not walk away without stirring at the end. The peas love to settle and grab the bottom, then it scorches, and you will be slightly grumpy like I was.
• I tried to blitz the whole pot super smooth once. It went from cozy to baby food fast. A few pulses, not a full purée, is my move now.

FAQ, the questions friends actually ask me

Can I make this on the stove Yep. Simmer everything in a big pot for about 60 to 75 minutes, stirring now and then. Keep the heat gentle and add water if it thickens too much.

Do I need to soak split peas No soaking needed. Rinse and you are good. If yours seem older, they might take longer so plan a bit of wiggle room.

Can I use ham or bacon if I am not vegetarian Sure, toss in cooked bacon or a ham rind for flavor. But the vegetarian version really holds its own, promise.

What cheese is best for the croutons I like sharp cheddar. A slice of provolone with a bit of cheddar is lovely too. If you bake bread, I love this simple sandwich loaf from King Arthur Baking, slices like a dream.

Can I prep this ahead Yes. Load everything in the slow cooker insert the night before and refrigerate. In the morning, pop it back in the base and cook. If your insert is cold, add the broth last so it warms gradually.

Why is my soup too thin Let it simmer longer with the lid cracked or mash some of the peas. A small handful of rolled oats added in the last 15 minutes thickens quietly.

Any resource for slow cooker quirks This primer from Serious Eats helped me learn why some cookers run hot and how to adjust.

Psst If you landed here for the exact phrase, yes, this is my beloved Slow Cooker Vegetarian Split Pea Soup with Grilled Cheese Croutons. It is a mouthful to say and a very pleasant one to eat.