Prepare the Beef: Divide the ground beef into 2 ½ ounce portions and gently roll them into balls. Avoid overhandling the meat to keep the patties tender.
Preheat the Flat Top: Set your flat top or griddle to high heat, keeping it ungreased. This step is crucial for achieving crispy, juicy beef. If you're using a pan, add 1 tablespoon of oil.
Smash the Tacos: Press the beef onto each tortilla & place face down onto flattop or pan. Use a heavy-duty smashing tool to press the meat down firmly, flattening it as much as possible under the tortilla. Let it cook for 1 minute, then press down again to release some fat, which will help the edges crisp up. Continue cooking for another 2-3 minutes without disturbing.
Check for Crispiness: Using a stiff steel spatula, carefully scrape underneath one of the patties to check if it's browned and crispy. If not, increase the heat to ensure the grill is smoking hot. Once browned and crisp, flip the smash burger tacos so the tortilla side is on the grill. Now sprinkle about ½ a teaspoon of salt & cook for an additional 2 minutes, allowing the tortilla to crisp up. Top with a slice of Muenster cheese, letting it melt as the tortilla finishes crisping.
Serve: Remove the smash tacos from the grill, add your desired toppings like mayonnaise, and enjoy!