Prepare merlot sauce by melting the 2 tbs of butter in a heavy skillet over medium heat. Add mushrooms and onion. Saute
stirring occasionally until onion begins to get golden brown and mushrooms begin to brown.
Add merlot, bring to boil and reduce the sauce to 50%. Add enough cream (heavy, light or half and half) until desired consistency is reached. The 1/2 cup is only a guide!! Ideally, sauce should "coat a spoon" and not be too runny. Add salt and pepper to taste. Sauce may be kept warm while cooking burgers.
In a large bowl, combine ground beef, gravy mix, onion, salt and pepper. Mix well. Divide mixture into 8 4-oz portions. Form each portion into a patty about 1/2-inch thick.
Place 2 tbsp of blue cheese and 1/4 of the diced bacon in the center of 4 of the patties. Top with the plain patties and seal well around the edges.
Heat a BBQ grill or broiler to high heat. Grill patties to desired doneness. For medium-well (160 degrees F) this should take approximately 5 minutes per side.