Preheat oven to 350°F. Toss onions, 1 tablespoon of the oil, salt and pepper together in a small roasting pan. Transfer to oven and roast until onions are tender. Set aside.

Heat 1 tablespoon of the butter in a medium skillet over medium heat. Add shallots and cook until softened. Stir in red wine cook until reduced to about 2 tablespoons. Set skillet aside to let cool slightly, then transfer red wine reduction to a medium bowl. Add remaining 3 tablespoons butter, 1 teaspoon of the parsley, salt and pepper and stir well. Set red wine butter aside. Sprinkle thyme and 1 tablespoon of the parsley on the salmon, then wrap each fillet with 2 slices pancetta. (The pancetta should not cover the fish completely). Grill salmon on a preheated grill until medium rare. Meanwhile, heat remaining 1 tablespoon oil in a large skillet. Add escarole, roasted onions, salt and pepper and cook until just wilted. Add broth and 1 tablespoon of the red wine butter and toss well. Remove from heat, then stir in salt, pepper, a squeeze of lemon and remaining 2 tablespoons parsley.

Divide escarole mixture among 4 plates, then arrange a piece of salmon in the center of each plate. Spoon remaining red wine butter over salmon. Once butter is somewhat melted, squeeze lemon wedges over the top and serve.