Authentic greek chicken souvlaki

Ingredients

• 2 large boneless, skinless chicken breasts
• 1/2 tsp dried oregano, preferably Greek
• 2 Tbsp extra-virgin olive oil
• Juice of half a lemon
• 1 8 oz container fat free Greek yogurt
• 1 2-inch piece of cucumber, peeled and grated
• 1 clove of garlic, minced
• 1-2 tsp lemon juice
• 1 Tbsp chopped fresh oregano, mint or dill
• 2 tsp extra-virgin olive oil
• Sea salt, to taste