Cut the buns in half horizontally. Roast on the cut surfaces in 4 portions in a pan without fat for approx. 1 minute, let cool off. Wash the lemon hot, rub dry. Finely grate half of the peel. Squeeze one half.
Use the remaining halves for other purposes. Clean, wash and drain the spinach. Wash the asparagus, cut off the woody ends. Cut asparagus into large pieces. Heat 2. oil in a pan. Fry the asparagus for about 4 minutes, turning them over. Season with salt and pepper. Remove from the pan and let cool off. Wash the prawns and dab them dry.
oil in a pan. Fry the asparagus for about 4 minutes, turning them over. Season with salt and pepper. Remove from the pan and let cool off. Wash the prawns and dab them dry. Fry in the pan in the frying fat for 2-3 minutes, turning over. Place in a bowl and season with salt, pepper, 1 tablespoon lemon juice and zest.
Cover the underside of the rolls with 1/4 each of the asparagus, shrimps and spinach. Drizzle with chilli sauce and place the top of the roll on top