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.