Your traditional patty melt... but animal style. Melty American cheese, caramelized onions, thousand island dressing, and pickles make the normal patty melt that much more delicious.
Mix the mayo, ketchup, mustard, relish, and salt together until well combined. Keep in the fridge, covered, until ready to use.
Slice your onions into very thin half moons.
Add your vegan butter and olive oil to a skillet over medium heat until melted and slightly sizzling. Add in your onions, sugar, and salt.
Allow the onions to cook, stirring relatively frequently, for 20-30 minutes until they're caramelized and significantly shrunken down.
Add your olive oil to a skillet over medium heat & allow it to heat up. While your oil is heating, brush both sides of your burger patty with yellow mustard.
Add your mustard covered patties to the skillet and cook for about 2-3 minutes on each side until they're golden brown, just keep an eye on them so you don't burn them. Remove them from the heat and set aside to cool slightly.
Wipe out your pan and then add in your vegan butter. Place your white bread in the pan, and add 1 slice of American cheese to each piece of bread. Once they start to get melty, add a big dollop of thousand island on each piece of bread, and a big spoonful of caramelized onions to 2 of the slices of bread, as well as a few pickle slices. Add your burger patty right on top of the onions & pickles.
Close the sandwiches and press down with a spatula to make sure everything sticks together. Transfer to a cutting board and allow to cool for a minute or so before cutting if you so desire.