For jalapeno sour cream sauce: Whisk all ingredients in a small bowl and season to taste. Set aside. Heat a large heavy skillet over high heat. When hot, add enough oil to cover bottom of pan and one more Tablespoon. Add sliced onion and reduce heat to medium-high. Cook and toss for about 20-30 minutes to caramelize. Remove to a bowl. Fry bacon in the same skillet until browned, remove to paper towel lined plate. In a small saucepan, mix together 1 Tablespoon Worcestershire sauce, ketchup and honey over low heat. Cook until mixture comes to a boil, removed from heat.
In a large bowl, mix together ground beef, 1/2 chopped onion, parsley, 1 Tablespoon Worcestershire sauce, jalapeno and salt. Form into patties. Prepare a grill. Grill burgers for 5 minutes, turn and baste with glaze. Burgers should be grilled to well-done. To serve, place a lettuce leaf on each serving plate, top with a burger then top with cheese and about 1 Tablespoon sauce, 2 slices of bacon and finally a dolop of caramelized onions. Serve immediately.
This is definately not low-fat, but it in worth the indulgence!