Heat a large pot over medium heat. Add the neutral oil, then add the onion and cook for 3-4 minutes, or until softened and translucent.

Add the garlic, red bell pepper, and green bell pepper. Cook for 2-3 minutes, or until softened and aromatic.

Add the tomato paste and cook for 1-2 minutes, stirring often, until it darkens slightly. Add the diced tomatoes, bay leaves, smoked paprika, cumin, chili powder or chili flakes, sugar, salt, and pepper. Mix well and cook for 2-3 minutes.

Add the lentils and 4 cups vegetable broth. Mix well, then bring to a boil over medium high heat.

Lower the heat to medium low, cover, and simmer for 20-25 minutes if using easy-cook lentils, or until tender to your liking. I like my lentils tender but still with a good bite. Stir occasionally to prevent the lentils from sticking to the pot.

Add more vegetable broth as needed, especially if using regular lentils. For a thinner soup, add more broth. For a thicker, stew-like soup, simmer uncovered for a few more minutes.

Taste and season with more salt, pepper, cumin, chili, or sugar if needed. Turn off the heat, then finish with fresh lemon juice and chopped parsley or cilantro.