In a large bowl, mix together the ground beef, panko breadcrumbs, egg, garlic powder, and Montreal steak seasoning until just combined. Don’t overmix. Divide into 7 equal portions and shape into wide, thin burger patties. If using the small tortilla bread, spread the bread mixture over the entire tortilla bread. If using a large tortilla bread, put the meat mixture on half the tortilla bread.
Heat a skillet or grill pan over medium heat. Melt a bit of butter. Place one tortilla in the pan, ground beef side down. Flip after 3-4 minutes.
Add a slice of cheese, a scoop of pico de gallo, lettuce and top with another slice of cheese. Place a second tortilla on top and press gently. Or if using the large tortilla bread fold in half to cover. Cook for 2–3 minutes more, until golden and crispy on both sides and the cheese is melted. Repeat with remaining ingredients.
Slice each quesadilla burger into halves or quarters. Serve with extra pico de gallo, sour cream, or guacamole if desired.
