Pat flank steaks dry with paper towels and place in shallow dish.
Combine soy, cayenne, cumin and vegetable oil. Rub mixture into meat, coating both sides evenly. Sprinkle with Montreal Steak Seasoning or coarse salt and black pepper and let stand.
Heat nonstick griddle or large nonstick skillet over high heat. When pan is over hot, place meat onto skillet or grill and cook for 5 minutes. Reduce heat to medium-high. Turn steak over and cook 10 to 12 minutes more. Place a loose foil tent over meat to reflect heat and control spattering. Remove meat from pan and let stand.
Return pan to heat and add a Tbsp of oil. Add onions and cook 10 minutes or until soft and golden brown. Cover the onions to smother them while they cook. When onions are just (about done, add a second skillet to stove and heat the pan over highest setting. Cook tortillas in a dry preheated pan 30 seconds on each side for each tortilla and pile up on a work surface or cutting board. Shred the flank steak meat with a very sharp knife by slicing the meat very, very thin, holding your carving knife on an extreme angle and working against the grain across the meat.
To assemble, paint a tortilla with steak sauce using a pastry brush. Pile meat, smoked shredded cheese and onions down the center of tortilla. Tuck the top and bottom edges of wrap in and twist the tortilla a quarter turn. Wrap and roll meats up into a burrito shape. Split each wrap in two with a cut across the middle of the wrap.Servings: 4