Heat the olive oil in a large pot over medium heat. Add the chorizo slices and cook until they release some fat and turn lightly browned.
Add the onion and bell peppers. Stir and cook for about 5 minutes until the vegetables soften.
Stir in the garlic and smoked paprika. Cook for 1 minute until the paprika smells fragrant.
Add the rinsed lentils, chicken broth, and diced tomatoes. Bring the mixture to a boil.
Reduce the heat to low, cover the pot, and simmer for 30 to 35 minutes until the lentils are tender.
Season with salt and black pepper to taste. Stir in the chopped parsley just before serving.