Clean, wash and drain the shrimp. The drier they are, the easier it will be to develop a thick sauce. Put the shrimp in a bowl and refrigerate until ready to put on the stove.
Heat the oil in a heavy skillet. Add the onions and PEPPER. Toss well and let cook over medium-low until the onions are slightly caramelized--getting sticky and brown, 8-10 minutes. Add the vinegar and hot sauce/CAYENNE. Raise heat to medium-high, let cook until the sauce reduces to a nice syrupy consistency. Add the shrimp and mushrooms. If using fresh shrimp, cook until pink (done), 3-5 minutes. If using pre-cooked, heat thoroughly, 1-2 minutes. Remove the shrimp to a plate. Continue cooking the sauce until it's once again reduced and syrupy--use your own judgment on how thick you want it. Pour over the shrimp and serve immediately.
Prep. time: 10 minutes
Cooking time: 20 minutes
Servings 3; Serving Size 1 cup (170g); Calories 180; Calories from fat 60; Total fat 7g; Cholesterol 85mg; Sodium 95mg; Carbohydrate 16g; Dietary Fiber 2g; Sugars 9g; Protein 13g.