Burger with Blue Cheese, roasted onions & mustard sauce | Castello®

Ingredients

• 4 slices of Castello® Burger blue
• 4 burger buns
• 450 g beef mince
• salt
• ground pepper
• 2 red onions, in thick slices
• 4 green lettuce leaves
• 2 tomatoes, sliced
• 4 whole pickles
• 250 ml sweet mustard, such as French’s
• 4 tbsp acacia honey
• 50 ml apple apple cider vinegar
• 2 tbsp red chillies, finely chopped
• 2 tbsp tomato ketchup
• 2 tsp worcestershire sauce
• ½ tsp garlic powder
• ground black pepper
• fries or potatoes wedges
• fresh thyme for sprinkling