Prepare the sauce: Art. spoons of olive oil mixed with 1 tbsp. l. light wine vinegar, 1 tsp Dijon mustard and 2 cloves of garlic, passed through a press.
Cut red onion into half rings, pour vinegar mixed with boiled water, and leave to marinate. Now we cut the breast, boiled until tender.
Cut the orange into slices, without white fibers, cheese into cubes. Arrange lettuce leaves on a platter, top with chicken fillet, onion, feta cheese and orange.