Dice onion, carrots, garlic, bell pepper, sweet potato, and Yukon Gold potato.
In a large soup pot, sauté onion, garlic, carrots, and bell pepper, with a splash of broth/water for 5–6 minutes.
Stir in cumin, smoked paprika, and turmeric. Cook for 1 minute.
Add lentils, sweet potato, and Yukon Gold potato. Stir well.
Pour in broth, water, and bay leaf. Bring to a boil, then reduce the heat to low, cover, and simmer for 25–30 minutes, or until the lentils and potatoes are tender.
Remove bay leaf. Blend part of the soup (or all of it) with an immersion blender for added creaminess, or leave it chunky.
Stir in lemon juice, season with salt and pepper.
Serve hot, garnished with fresh parsley or cilantro.