Combine burger ingredients in a bowl and form into patties
Combine onion ingredients in skillet, cover and simmer for 15 min or until tender
Combine sauce ingredients in small saucepan and simmer, stirring occasionally until creamy
Cook the burgers, when they are almost done season slices of avocado with seasoned salt and place them on the grill for 2 min a side
Serve on toasted pretzel bun. Bun, lettuce, tomato, burger, caramelized onion, bacon, avocado, cheese spread on top bun.