Wash potatoes well and cook covered for about 20 minutes. Wash fish inside and outside and dab dry. Wash parsley and rosemary, shake dry. Wash lemon hot, grate dry and cut into slices.
Season fish inside with salt and pepper. Fill with herbs, bay leaves and lemon slices. Spread with a little oil.
For the salad dressing, mix vinegar, salt, pepper and 1 pinch of sugar. Fold in 2 tablespoons of oil. Wash the salad and shake dry. Wash and chop the tomatoes.
Drain the potatoes and place them in the grill tray. Grill the fish in a fish grill tongs on the hot grill for 6-8 minutes on each side. Add potatoes to the grill tray and grill briefly.
Mix lettuce, tomatoes and vinaigrette. Arrange everything.