Flying Dutchman Burger

Name: Flying Dutchman Burger
Ingredients: 4 oz Vegan Meat ((like Impossible or Beyond, SEE NOTES)); 2 Slices Vegan American Cheese; 1 Burger Bun ((optional)); Mustard; 1 Yellow or Brown Onion; Neutral Oil ((Vegetable, Canola, etc)); Salt; 1 cup Vegan Mayo; 1/4 cup Ketchup; 2 Tbsp Dill or Sweet Relish; 1 Tbsp Vegan Worcestershire; 1 tsp Garlic Powder; Salt & Pepper ((to taste))