Thaw the burger patties in the fridge before cooking.
Pan method: Preheat a pan on medium-high heat and add 1 tsp of cooking oil. When hot, pan-fry for 4 minutes, flip and reduce to medium-low, pan-fry for 3 minutes. Flip and fry for one more minute or until lightly charred.
Barbecue method: Brush both sides of a patty with oil, then grill on medium heat for 12 minutes, flipping occasionally, until lightly charred.
In the meantime, slice/chop the onion, tomato, red cabbage, and prep the other ingredients.
Make the Thousand Island dressing by mixing all ingredients in a small-medium bowl with a whisk. Use less water for a thicker sauce and more for a thinner dressing.
You can warm the burger buns in the pan (or on the grill) for a few minutes if desired.
Assemble in this order: Bottom burger bun, lettuce, tomato, red cabbage, burger patty, vegan cheese, homemade Thousand Island dressing, more lettuce, top burger bun.
Serve immediately and enjoy!