Preheat: oven to 400 degrees
Roast: Toss the carrots and bell pepper in 1 tbsp of olive oil. Arrange in single layer on a baking sheet and bake for 15-20 minutes. Flip the vegetables over halfway through.
Broil: Turn on the oven broiler and cook for an additional 3 minutes, watch the vegetables to ensure they don't burn or overcook. You want to see some color on the carrots and peppers, but not black charring. Remove from the oven and set aside to cool. Using a pairing knife, carefully peel the skin off the bell peppers.
Toast Spices: While the vegetables are baking, heat a large soup pot over medium heat. Once hot, dry roast the cumin and chili flakes until aroma is released, usually about 1 minute.
Sauté Onion: Add 1 tbsp of olive oil to the pot with the spice, add the red onion and sauté until onion has softened.
Simmer: Add vegetable stock, red lentils, roasted vegetables, and diced tomatoes to the pot. Bring to a boil, then reduce to a simmer. Allow the soup to simmer until the lentils are fully cooked, about 15 minutes.
Blend: Remove soup from the heat and allow to cool slightly. Pour half the soup into a blender and pulse until smooth. Alternatively, use an immersion blender and roughly blend in the pot leaving lots of chunks, but thickening the broth.
Add Chickpeas: Add the blended soup back into the pot and mix in chickpeas. Season the soup to taste with salt and pepper and serve with Greek yogurt or sour cream and chopped parsley.