Tater tot patty: cut a small piece of parchment or wax paper to about 5 inches square. Add a little oil to the top or spray it with non-stick spray.
If your tater tots are still frozen, you can microwave them for 45 seconds to 1 minute until they are soft enough to use. Once they are thawed, sprinkle them with a little bit of salt and black pepper and mash them with a fork and form them into a patty on top of the piece of parchment. If you have a biscuit cutter that is around 3.5 to 4 inches in diameter, you can use that for a consistent size. Otherwise, form into a patty and then leave on the parchment until ready to cook.
Place two skillets or a skillet and a grill pan over medium heat.
In a large skillet, add 1 to 2 teaspoons of oil. Once the oil is shimmering, carefully add your tater tot patty. Use the piece of parchment to carefully place the potatoes into the hot pan on top of the oil. Cook the tater tot patty for 5 minutes on the first side before flipping.
While the tater tot patty is cooking, add salt and pepper to your sliced red onion and place it on the medium heat grill pan or a second skillet. Cook onions until they are softened, about 6 or 7 minutes. Move them to a bowl when they are done.
Prepare the seasoned flour: add flour, paprika, garlic powder, onion powder, black pepper, and salt to a small plate and stir to ensure the flour is fully seasoned.
If your cube steak was not pounded by the butcher, pound it out now with a meat mallet to tenderize. Once the steak is pounded, add it to the plate with the seasoned flour. Coat cube steak on both sides with flour.
Slide the tater tot patty over to one side of the pan and add butter to the empty side. The butter should quickly start to melt and bubble. At this point add the flour-dusted steak and cook for 3 to 4 minutes per side.
Once the tater tot patty has cooked for 5 minutes, carefully flip and continue to cook for an additional 4 minutes or until the steak is ready to remove from the pan.
Remove both the tater tot patty and the steak and add to a cutting board or cooling rack to rest for 3 to 5 minutes.
Sandwich assembly: Slice your bun and toast it if you prefer.
Add a scoop or two of guacamole to the bottom bun and then top that with your steak. Add the tater tot patty and some crumbled cheese and a few grilled onions. Top the whole thing with your favorite hot sauce if desired.
Serve and enjoy.