In a large bowl add Hamburger, Ranch Dressing and mix well. Divided into 6 sections to create 6 Hamburger Patties. Press thumb in the middle of each patty to reduce shrinkage during cooking. Cook on a grill to desired likeness. When nearly done, place cheese on burger and let melt. While burgers are cooking slice onion and set aside.
On medium-high heat add Butter to deep frying pan. Add onions and cook for 1 minute. Add Minced Garlic and stir. Add Cognac and mix well. Add mushrooms cook for 1-2 minutes then season with Garlic Salt, Salt and Pepper to taste. Cook until Mushrooms and Onions become fork tender.
While Onions and Mushrooms are cooking in a small bowl whisk together Mayo and Steak Sauce and set aside.
Place Cheeseburger on a bun, top with Mushrooms and Onions then smother with sauce. Enjoy!