Spanakopita Stuffed Chicken Burgers with Tzatziki recipes

Name: Spanakopita Stuffed Chicken Burgers with Tzatziki recipes
Ingredients: 1 lb. chicken breast; 8 oz. fresh baby spinach; 1 + ⅛ tsp. salt; ⅛ tsp. nutmeg; Pinch of pepper; 5 oz. feta cheese, divided; 2 garlic cloves, grated; 1 small onion, (1/2 grated, ½ finely chopped); 1 tsp. oregano; 1 Tlbs. +1 tsp. olive oil, divided; 1 tomato, sliced thin; purple onion; 4 hamburger buns; 1 cup grated cucumber, (squeezed of all excess moisture); 8 ounces plain Greek yogurt; 1 small garlic clove, grated; 2 teaspoons lemon juice; ¼ teaspoon salt; ½ teaspoon fresh dill; 1 teaspoon olive oil