1 lb. ground beef (95% lean) 1/4 c. low-fat or regular plain Greek-style yogurt 1/2 c. olive tapenade, divided 1 small sweet onion, thinly sliced 1 small zucchini, thinly sliced 1/4 c. crumbled feta cheese 4 whole-grain hamburger buns, split, toasted Fresh spinach leaves
What to do:
1. Combine yogurt and 1/4 c. tapenade in small bowl. Cover and refrigerate until ready to use. 2. Combine ground beef and remaining 1/4 c. tapenade in large bowl, mixing lightly but thoroughly. Lightly shape into four 1/2-in. thick patties. 3. Heat grill pan over medium heat until hot. Place patties in pan; cook 10-12 min. until instant-read thermometer inserted horizontally into center registers 160°F, turning occasionally. Season with pepper, as desired. Remove; keep warm. 4. Add onion and zucchini to grill pan over medium heat; season with salt and pepper, as desired. Cook 5-6 min. or until lightly browned and crisp-tender, turning occasionally. 5. Place 1 Tbsp. cheese on bottom of each bun; top evenly with spinach leaves, onion, burger and zucchini. Spread 2 Tbsp. yogurt mixture on cut side of each bun top. Close sandwiches.
