Step-by-Step Instructions
Slow Cooker Method
Step 1 - Load everything at once. Add the chopped onion, carrot, celery, peeled and chopped potatoes, green beans, fire-roasted diced tomatoes (with all their liquid), tomato paste, bay leaf, smoked paprika, garlic powder, vegetable stock, and kosher salt directly to the slow cooker. Stir everything together so the tomato paste and spices distribute evenly through the broth rather than sitting in concentrated patches.
That's the entire active cooking step. Seriously. Everything goes in raw and the slow cooker handles the rest completely independently.
Step 2 - Cook until tender. Cover the slow cooker and cook on HIGH for 4–5 hours or LOW for 7–8 hours. The soup is ready when all the vegetables are completely tender the potatoes should have no resistance when pierced with a fork, the carrots should be soft throughout, and the green beans should have lost their crispness entirely.
The potatoes will naturally release some of their starch into the surrounding broth during the long cook, thickening it slightly and giving the soup a more unified, velvety quality than the vegetable stock started with. This self-thickening effect is one of the best features of potato-inclusive slow cooker soups.
Step 3 - Add corn and peas at the end. Remove the lid and stir in the corn kernels and peas. These go in during the final 15–20 minutes for frozen (already defrosted) versions, or just before serving for fresh versions. The residual heat from the hot soup thaws and warms them completely without overcooking they stay bright, slightly sweet, and texturally distinct from the vegetables that cooked for the full duration.
Remove the bay leaf. Taste and add additional salt if needed. Serve immediately.
Stovetop Method (Faster Alternative)
Step 1 - Heat 1 tablespoon olive oil in a large pot over medium heat. Add the chopped onion with a pinch of salt and cook for 5 minutes until softened. Add the carrot and celery and cook for another 5 minutes.
Step 2 - Add the potatoes, green beans, fire-roasted tomatoes, tomato paste, bay leaf, smoked paprika, garlic powder, and salt. Stir to combine. Add the vegetable stock, cover, and bring to a boil.
Step 3 - Reduce to a simmer and cook covered for 25–35 minutes until all vegetables are completely tender.
Step 4 - Add corn and peas, stir, and let warm through for 2–3 minutes. Taste and adjust salt. Serve.
The stovetop version produces a nearly identical result in significantly less time. The primary advantage of the slow cooker version is the hands-off cook time the stovetop version requires someone to be home and monitoring throughout.
