01 - Set oven to 425°F and prepare for roasting red bell peppers.
02 - Slice peppers in half, remove seeds and membranes, then place cut side down on a parchment-lined baking sheet.
03 - Roast for 20-25 minutes until skins blister and char, then transfer to a bowl, cover, and steam for 10 minutes before peeling and chopping the flesh.
04 - Heat olive oil over medium heat in a large pot, then add onion, carrot, and celery. Cook for 5-7 minutes until softened.
05 - Mix in garlic, smoked paprika, ground cumin, and chili flakes; cook for 1 minute until aromatic.
06 - Stir in chopped roasted peppers and rinsed lentils. Pour in vegetable broth.
07 - Bring to a boil, then reduce heat and simmer uncovered for 20-25 minutes until lentils soften.
08 - Purée the soup with an immersion blender or in batches using a countertop blender until smooth or slightly chunky as preferred.
09 - Adjust seasoning with salt and black pepper.
10 - Ladle hot soup into bowls and garnish with fresh parsley and lemon wedges.