Feta Burgers With Grilled Red Onions

From Bon Appetit, July, 2007. These newfangled burgers are stuffed with feta cheese. Pressing the center of the raw hamburger to form a slight indentation prevents the burger from puffing up in the center when cooking. Here for safe keeping and sharing.

• Ready In: 25 mins
• Serves: 8

Ingredients

• 3  lbs lean ground beef
• 1  cup feta cheese, packed, crumbled
• 2  teaspoons dried oregano
• 1 1⁄2 teaspoons salt
• 1 1⁄2 teaspoons ground black pepper
• 8  large garlic cloves, peeled
• 1⁄2 cup extra virgin olive oil
• 1  teaspoon extra virgin olive oil
•  nonstick  vegetable oil cooking spray
• 2  medium red onions, peeled, each cut crosswise into 4 slices
• 8  hamburger buns
• 2  large tomatoes, each cut crosswise into 4 slices

Directions

1. Break up beef in large bowl.
2. Sprinkle feta, oregano, salt, and pepper over (meat); toss.
3. Divide into 8 portions; form each into 4 1/2-inch burgers, pressing in center to form slight indentation. *DO AHEAD Can be made 1 day ahead. Cover; chill.
4. Puree garlic in processor; With machine running, gradually add 1/2 cup oil; process 30 seconds. *DO AHEAD Can be made 1 day ahead. Cover; chill.
5. Spray grill rack with nonstick spray.
6. Prepare barbecue (medium-high heat).
7. Brush onion with 1 tablespoon oil; sprinkle with salt and pepper.
8. Place burgers and onions on grill. Cover; cook 5 minutes.
9. Turn onions and burgers; cook until onions are charred in spots and burgers are medium-well, about 4 minutes longer.
10. Transfer to plate. Brush cut sides of buns with garlic oil and place buns, cut side down, on grill; toast about 1 minute.
11. Turn buns; cook until heated, about 1 minute.
12. Place burgers on bun bottoms and top each with onion, tomato, and bun top.