Peel and chop the onion and garlic. Clean, wash and chop the peppers. Heat 2 tablespoons of oil in a saucepan. Sauté onion, garlic and paprika in it. Add the tomatoes and chop them coarsely in the pot with a spatula. Season with salt, pepper and sugar. Simmer for about 20 minutes.
Wash and peel the asparagus and cut off the woody ends. Cook the asparagus in boiling salted water with 1 teaspoon sugar for about 12 minutes. Drain, rinse with cold water and let drain. Spread the asparagus in a casserole dish. Wash parsley, shake dry. Pluck off leaves and chop finely. Mix parsley with the sauce, except for a little bit for sprinkling. Flavour the sauce again and spread on the asparagus. Crumble the feta and sprinkle over it. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 12-15 minutes
Wash the prawns, dab dry. Heat 2 tablespoons of oil in a frying pan. Fry the prawns in it for about 2 minutes on each side. Season with salt and pepper. Take Saganaki out of the oven, spread prawns on top. Sprinkle with parsley that has been set aside. Serve immediately