Rinse the lentils under cold water until the water runs clear; drain and set aside.
Prepare the vegetables: peel and finely chop the onion; peel and mince the garlic; dice the green bell pepper; peel and slice the carrots; peel and chop the potato into medium chunks.
Heat 2 tablespoons of extra-virgin olive oil in a large pot over medium heat. Add the chopped onion and cook until translucent, about 5 minutes.
Add the minced garlic and diced bell pepper; cook for 5–7 minutes, until softened and fragrant.
Stir in the sliced carrots and cook for 2 more minutes.
Remove the pot from the heat. Sprinkle in the smoked paprika and stir quickly to prevent burning.
Return the pot to medium heat. Add the lentils, potato chunks, and bay leaves. Pour in enough vegetable broth (or water) to cover the ingredients by about 1 inch. If desired, add a pinch of ground cumin.
Bring to a boil over high heat, then reduce to medium-low. Partially cover and simmer for 40–50 minutes, stirring occasionally and adding more liquid if needed, until the lentils are tender.
Season with salt to taste. For a thicker stew, mash or puree a portion of the lentils and vegetables, then stir them back in.
Serve the stew hot, with crusty bread on the side for dipping.