Chicken sausage burgers with balsamic onion barbecue sauce Recipe | Food Network UK

Ingredients

• Extra-virgin olive oil, for liberal drizzling plus 2 tbsp.
• 115g pancetta, chopped
• 2 red onions chopped
• Salt and black pepper
• 1 fresh bay leaf
• 1 kg ground chicken
• 1 1/2 tbsp. fennel seed, lightly toasted
• 1 tsp. crushed red pepper flakes -- go heavier for extra spicy
• 1/4 tsp. allspice
• Zest and juice of 1 orange
• 3 tbsp. finely chopped rosemary, 4 to 5 sprigs
• 4 cloves garlic, grated with a microplane or the small side of a box grater
• 2 generous handfuls of grated Parmigiano Reggiano or Romano cheese
• 2 tbsp. Worcestershire sauce, eyeball it
• 125ml aged balsamic vinegar
• 3 tbsp. honey or dark brown sugar
• 1/2 endive, chopped
• 40g arugula leaves, shredded
• 1/2 radicchio, chopped
• 4 crusty baps, split, toasted and drizzled with extra-virgin olive oil or buttered