Preheat the oven to 425 degrees. Cut the red bell peppers and tomatoes into large pieces and place them on a baking sheet with the onion and garlic cloves. Drizzle with olive oil and roast for 25 minutes until the edges start to char.

Transfer the roasted vegetables to a blender. Add the vegetable stock and smoked paprika. Blend until completely smooth.

Pour the mixture into a small saucepan. Heat over medium until warmed through, then season with salt and black pepper to taste.

Divide the soup among four small shooter glasses. Top each with one basil leaf before serving.