Chicken sausage burgers with balsamic onion barbecue sauce

This mouth-watering recipe is ready in just 35 minutes and the ingredients detailed below can serve up to 4 people.
Ingredients
Method
2) While the onions cook, place the ground chicken in a bowl and add fennel seed, red pepper flakes, allspice, orange zest, rosemary, garlic, salt and pepper, to taste, and cheese. Mix the meat with seasonings and form 4 large patties. Make a shallow dent in each patty at the center of it to prevent the burger from bulging up as it cooks. Wash up and drizzle the patties liberally with extra-virgin olive oil. Place the patties on the barbecue and cook 6 to 7 minutes on each side.
3) When the onions are very soft and begin to caramelize, remove the bay leaf and add the Worcestershire sauce, balsamic vinegar, honey or sugar, and orange juice. Let the sauce thicken up and sweeten up 6 to 7 minutes until the liquids are syrupy. Adjust the black pepper level to your taste.
4) Mix the chopped endive, shredded arugula and chopped radicchio together. Pile the chopped lettuces on the bap bottoms top with burgers and lots of onion barbecue sauce. Set bap tops in place and serve.