Defrost the prawns if necessary. Clean the chillies, cut lengthwise, remove seeds, wash and cut into fine rings. 3⁄4 Mix the chilli and the Sriracha sauce. Twist off the head of the prawns. Peel the prawns and remove the guts. Wash the shrimps, dab dry and marinate in the chilli sauce for about 20 minutes.
Halve the avocados, remove seeds and pulp. Mash with a fork. Season to taste with lime juice, rest of chilli, salt and pepper.
Wash the radicchio and dab dry. Knead minced meat, 4 tablespoons Teriyaki sauce and 1⁄2 tsp. pepper. Form 4 burger patties.
Cut the buns in half. Roast the cut surfaces in a large pan without fat, remove. Heat the oil in the pan. Remove the prawns from the marinade and fry on each side for about 2 minutes. Remove and keep warm. Fry the patties in hot frying fat for approx. 4 minutes on each side, pouring the rest of the Teriyaki sauce over them halfway through the frying time. Cover with cheese and let cheese melt.
Spread all bread roll halves with avocado cream. Spread the radicchio, burger patties together with the frying set and prawns on top. Put the top of the buns on top.