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Slow Cooker Lentil Vegetable Soup - Cozy, Hearty, and Effortless

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Prep Time 15 minutes
Cook Time 8 hours
Total Time 8 hours 15 minutes
Servings: 6 servings
Ingredients Method

Ingredients
  

  • Brown or green lentils (1 1/2 cups), rinsed
  • Yellow onion (1 medium), diced
  • Carrots (3 medium), diced
  • Celery (3 stalks), diced
  • Garlic (4 cloves), minced
  • Russet or Yukon gold potato (1 large), peeled and diced
  • Crushed tomatoes (1 can, 14.5 oz)
  • Vegetable broth (6 cups), low sodium preferred
  • Olive oil (1–2 tablespoons, optional for sautéing)
  • Bay leaves (2)
  • Ground cumin (1 teaspoon)
  • Smoked paprika (1 teaspoon)
  • Dried thyme or Italian seasoning (1 teaspoon)
  • Baby spinach or chopped kale (2–3 cups)
  • Lemon (1), for finishing
  • Salt and black pepper, to taste
  • Optional add-ins: red pepper flakes, chopped parsley, grated Parmesan (if not vegan), a splash of balsamic vinegar

Method
 

  1. Rinse the lentils. Place them in a fine-mesh strainer and rinse under cool water until it runs clear. This removes dust and helps them cook evenly.
  2. Prep the vegetables. Dice the onion, carrots, celery, and potato into bite-size pieces. Mince the garlic.
  3. Optional flavor boost: sauté the aromatics. In a skillet, warm olive oil over medium heat. Cook onion, carrots, and celery with a pinch of salt for 5–7 minutes until softened. Add garlic and cook 30 seconds more. This step deepens flavor but isn’t required.
  4. Load the slow cooker. Add lentils, vegetables, crushed tomatoes, broth, bay leaves, cumin, smoked paprika, and thyme. Stir to combine.
  5. Set and cook. Cover and cook on Low for 7–8 hours or High for 3–4 hours, until lentils are tender and the soup has thickened.
  6. Finish with greens. Stir in spinach or kale during the last 10–15 minutes of cooking. Kale may need a bit longer; add it 20 minutes before serving.
  7. Season and brighten. Remove bay leaves. Add 1–2 tablespoons of lemon juice, then season with salt and pepper. Taste and adjust—more acid and salt make the flavors pop.
  8. Adjust texture. For a creamier soup, use an immersion blender to blend 1–2 cups right in the pot, or mash a few scoops of potatoes and lentils with a spoon and stir back in.
  9. Serve. Ladle into bowls and finish with a drizzle of olive oil, red pepper flakes, chopped parsley, or a sprinkle of Parmesan if you like.