Chicken and Feta Salad

Ingredients

• 1/4 cup olive oil
• 3 tsp fresh oregano (chopped)
• 2 tbsp red wine vinegar
• 1 tbsp butter (for cooking)
• 400 grams chicken breast
• 1 large onion, red (peeled and cut into thin wedges)
• 300 grams feta cheese
• 150 grams baby spinach
• 250 grams cherry tomatoes (halved)
• 1/2 cup pitted Kalamata olives
• 1/2 tsp rock salt (to taste)
• 1/4 tsp black pepper