In a large pot, heat olive oil over medium heat.
Add chopped onions and garlic; sauté until translucent, about 5 minutes.
Stir in diced carrots and bell pepper; cook for another 3-4 minutes.
Add in the sweet potatoes, lentils, diced tomatoes, vegetable broth, cumin, paprika, thyme, and bay leaf.
Bring the mixture to a boil, then reduce heat to low and cover.
Simmer for 30-35 minutes, or until lentils and sweet potatoes are tender.
Season with salt and pepper to taste; remove the bay leaf before serving.
Ladle into bowls and garnish with fresh parsley.