Souvlaki with greek salad

Name: Souvlaki with greek salad
Ingredients: 750 gram rump steak, cut into 2cm cubes; 1 large (200g) brown onion, cut into wedges; 1/4 cup (60ml) olive oil; 1/4 cup (60ml) lemon juice; 1 tablespoon dried rigani (greek oregano); 4 medium (300g) egg tomatoes, chopped coarsely; 2 (260g) lebanese cucumbers, chopped coarsely; 1 small (100g) red onion, sliced thinly; 1 large (350g) green capsicum, chopped coarsely; 1/2 cup (80g) seeded kalamata olives; 150 gram feta cheese, chopped coarsely; 1 tablespoon olive oil; 1 tablespoon lemon juice; 2 teaspoon fresh oregano leaves