1 egg
1/4 cup (50 mL) dry bread crumbs
1/4 cup (50 mL) water
1 small onion, grated
2 tbsp (25 mL) sweet green relish
1 tsp (5 mL) Worcestershire sauce
1/2 tsp (2 mL) each dried oregano, salt and pepper
1 lb (500 g) lean ground beef
2 oz (60 g) sliced Swiss, Cheddar or mozzarella cheese
32 mini-buns or mini-pitas

In bowl, whisk egg, crumbs, water, onion, relish, Worcestershire sauce, oregano, salt and pepper; mix in beef. Form by rounded tablespoonfuls (15 mL) into 1/4-inch (5 mm) thick patties. (Make-ahead: Layer between waxed paper in airtight container and refrigerate for up to 1 day. Or freeze for up to 4 weeks; thaw in refrigerator.)

Place patties on foil-lined rimmed baking sheet; bake in 375°F (190°C) oven until no longer pink inside, about 10 minutes. Meanwhile, cut cheese into 1-inch (2.5 cm) squares; set aside.

Place burger patties on buns and garnish with Cheese, lettuce, tomatoes and pickles, or as desired.