2)In a small pan heat the brown sugar, Worcestershire sauce, vinegar, tomato sauce and black pepper, to taste. Simmer until the mixture becomes a thick sauce consistency, about 15 minutes.
3) Meanwhile, in a shallow pan of boiling, salted water cook the broccoli rabe for 5 minutes, then drain. Transfer to a board and cut 5cm pieces. Set aside.
4) Heat a drizzle of extra-virgin olive oil in the shallow over medium-high heat, add the burgers and cook for 5 to 6 minutes on each side. Top the burgers with a slice of provolone during the last minute of cooking and tent with foil to melt. Transfer the burgers to a plate and keep warm.
5) Return the pan to medium heat and add 1 tbsp olive oil. Stir in the chopped garlic and the broccoli rabe. Saute for 2 minutes, then season with a few grates of nutmeg, to taste.
6) To serve divide the broccoli rabe between the halved ciabatta rolls and top with the cheesy sausage burger. Slather some of the warm sauce on the top and serve.