Ingredients
1 tablespoon olive oil2 shallots, chopped2-1/2 cups fresh baby spinach, coarsely chopped3 garlic cloves, minced2/3 cup crumbled feta cheese3/4 teaspoon Greek seasoning1/2 teaspoon salt1/4 teaspoon pepper2 pounds lean ground beef (90% lean)8 whole wheat hamburger buns, splitOptional toppings: refrigerated tzatziki sauce, fresh baby spinach and tomato slices
Preparation
In a large skillet, heat oil over medium-high heat. Add shallots; cook and stir until tender, 1-2 minutes. Add spinach and garlic; cook until spinach is wilted, 30-45 seconds longer. Transfer to a large bowl; cool slightly.
Stir feta cheese and seasonings into spinach. Add beef; mix lightly but thoroughly. Shape into eight 1/2-in.-thick patties.
Grill burgers, covered, over medium heat until a thermometer reads 160°, 6-8 minutes on each side. Grill buns over medium heat, cut side down, until toasted, 30-60 seconds. Serve burgers on buns. If desired, add toppings.
