Cook the lentils in boiling water for about 20 minutes. Season with salt shortly before the end of the cooking time. Drain on a sieve. Peel and cut the onions into eighths. Clean peppers and zucchini and cut into strips.
Grill vegetables under the hot grill in the oven for 10-12 minutes or fry them with 1 tablespoon of oil in a hot grill pan for 8-10 minutes. Finely chop the rosemary. Chop garlic finely as well. Mix vinegar, mustard, garlic, broth, rosemary, salt and pepper. Fold in 6 tablespoons of oil. Mix with lentils and leave to stand. Fry meat in remaining oil in a grill pan for 3-4 minutes on each side, season with salt and pepper and cut into strips. Mix vegetables, rocket and lentil vinaigrette. Crumble the feta and pour over the salad with the meat.
Fold in 6 tablespoons of oil. Mix with lentils and leave to stand. Fry meat in remaining oil in a grill pan for 3-4 minutes on each side, season with salt and pepper and cut into strips. Mix vegetables, rocket and lentil vinaigrette. Crumble the feta and pour over the salad with the meat. Garnish with basil