Spinach and Feta Turkey Burgers

Name: Spinach and Feta Turkey Burgers
Ingredients: 16 oz. lean ground turkey; 1 tbsp olive oil; 1/2 cup feta cheese; 1 cup spinach (chopped); 1/8 cup panko crumbs (italian seasoned); 1/4 tsp pepper; 2 tsp worcestershire sauce; 1 tsp A1 steak sauce (optional); 4 hamburger buns; 1 mini cucumber; 1/2 red onion; 4 tbsp. light mayo