Apple and onion confit burger - La Pomme du Québec, Recipe

Ingredients

• 2 portobello mushrooms, thickly sliced
• 4 hamburger buns
• 4 Boston lettuce leaves
• 1 goat's cheese log (125 g), sliced into rounds
• 450 g (1 lb) lean ground pork
• 80 ml (⅓ cup) dry shallots (French), chopped
• 60 ml (¼ cup) quick-cooking rolled oats
• 60 ml (¼ cup) chopped parsley
• 15 ml (1 tablespoon) minced garlic
• 1 egg
• 1 Québec apple, grated
• 60 ml (¼ cup) calvados
• 125 ml (½ cup) brown sugar
• 15 ml (1 tablespoon) chopped thyme
• Salt and pepper to taste
• 2 large onions, thinly sliced