Mix pork mince, chorizo sausage, breadcrumbs, egg, apple and McCormick Grill Mates Classic all Star Burger Seasoning together. Shape into 8 patties.
BBQ or panfry patties for 4-8 minutes each side or until cooked through.
Brush olive oil or use cooking spray on both sides of onion slices. BBQ or panfry for 3 to 4 minutes on each side, turning carefully to keep slices whole.
To Build burgers; generously spread McCormick Grill Mates Brown Sugar Bourbon BBQ Sauce over base of bun, top with burger, then cheese, onion slice and spinach leaves. Finish with extra sauce and bun top.
Stick a bamboo skewer through the top of filled burgers to stop them toppling over.