Mediterranean Burger

Add 1 tablespoon olive oil to a skillet over low heat. Add the sliced onions and cook slowly, stirring often, until softened. Add 1 tablespoon balsamic glaze and continue cooking until the onions are deeply browned and very tender.

While the onions cook, add the ground beef to a mixing bowl. Mix in the egg, shredded cheddar cheese, and Worcestershire sauce until combined. Form the mixture into 6 large patties and set aside.

Preheat the oven to 400 degrees Fahrenheit. Place the frozen stir-fry vegetables in a mixing bowl, season with salt and pepper, and drizzle with 2 tablespoons olive oil. Toss well, then spread the vegetables on a sheet pan. Roast until tender and lightly browned around the edges. Remove from the oven, drizzle with 1 tablespoon balsamic glaze, and toss gently.

Grill the burgers over medium-high heat. When the first side is browned, flip them. Add a slice of mozzarella cheese to each burger and continue cooking until the burgers reach the desired doneness and the cheese is melted.

Top each burger with an even portion of the balsamic onions. Transfer the burgers to serving plates. Divide the roasted vegetables evenly over the burgers, then sprinkle each one with crumbled feta cheese. Finish each burger with 1 tablespoon balsamic glaze and serve immediately.