Slice the Button Mushroom (15). Dice the Yellow Onion (1).
Add the diced onions to a pan with Grapeseed Oil (1 tablespoon). Sauté them for 45 minutes to an hour. Add water from time to time to make sure they do not burn. While the onions caramelize, move on to the mushrooms.
Add the sliced mushrooms to a pan over medium high heat with Grapeseed Oil (1 tablespoon) and sauté them for 15 to 20 minutes. Check the heat, and reduce it to make sure they don't burn.
Chop the Chipotle Peppers in Adobo Sauce (1). Feel free to use more if you like your sauce hot.
To make Baby's Spice, combine the Garlic Salt (1 teaspoon), Salt (2 teaspoon), Old Bay® Seasoning (1 teaspoon), Paprika (1 teaspoon) and Chili Powder (1 teaspoon).
Combine the Ketchup (1 cup), Mayonnaise (1 cup), chopped Chipotle pepper, 1/2 tablespoon of Baby's Spice, and yellow Yellow Mustard (1/2 teaspoon) in a bowl. Refrigerate until needed.
Take your onions and mushrooms off the heat and set aside.
Divide the Ground Angus Chuck 80/20 (4 pound) and form eight equal patties. Make sure to press and indent into the middle of the patty. This will make sure it cooks evenly.
Add grapeseed oil (1 Tbsp) to a pan oven medium high heat. Season the side of the patty without the indent with baby's spice and place that side down on the hot pan.
Cook burgers to Medium- a little pink inside or to your own personal liking. Make sure to season the top side of the burger before flipping.
Add a spoonful of the carmelized mushrooms and onions.
Top with Swiss Cheese (8 slice). While the burger finishes cooking, begin toasting your King's Hawaiian® Bakery Sandwich Buns (8).
Take the buns off the grill and place a gnerous portion of Baby's sauce on the top bun. Place burger patty on the bottom bun and top with the saucey bun. Enjoy!