Fry the onion, garlic, carrot and celery in 4 tablespoons of oil until translucent. Add the potatoes and peppers and fry briefly. Top up with the broth and simmer gently with the bay leaf for 35 minutes. Then remove the bay leaf and puree with a blender and pass through a sieve. Then heat again, stir in the milk and season with salt.
Pour the soup into preheated plates, drizzle with the remaining oil, dust with a little paprika and sprinkle with a mixture of parsley and parmesan.
If red peppers are used, roast them beforehand in the oven at 250 degrees and then peel them.