2 pounds ground beef (15 to 20 percent fat content)
1 medium yellow onion, grated on the large holes of a box grater (about 3/4 cup), excess liquid discarded
1/2 cup shredded sharp cheddar cheese (about 1 ounce)
1/3 cup ketchup
1/4 cup fine, unseasoned breadcrumbs
1/4 cup coarsely chopped fresh Italian parsley
2 large eggs, lightly beaten
2 medium garlic cloves, finely chopped
2 tablespoons Worcestershire sauce
1 1/2 teaspoons kosher salt
1 teaspoon freshly ground black pepper
7 thick-cut bacon slices