3 stuffed burgers sourdough Recipes

lean ground beef, salt, divided, black pepper, divided, feta cheese, cut into 4 (1/2-oz) pieces, thick) red onion slices, extra virgin olive oil, divided, crusty sourdough bread slices, coarse-grained dijon mustard, plum tomato slices

dried parsley, worcestershire sauce, salt, garlic powder, freshly ground black pepper, shredded swiss cheese, sliced 33%-less-sodium smoked deli ham, sourdough bread, curly leaf lettuce leaves, thick) slices red onion, thick) slices tomato