Heat skillet with olive oil, on medium high heat. Slice beef into thin slices. Add beef slices to pan and cook until beef starts to brown. Add onions, peppers, mushroom and garlic. Cook until vegetables are tender. Add cumin, salt, pepper and stir. Remove from heat, cover so mixture stays hot and set aside.
Roll 4 large tortillas in paper towels and heat for 30 seconds in microwave. Remove and divide filling evenly among tortillas. Add cheese to each, fold sides and bottom in and roll into burritos. Serve warm with cheese gooey melted. Enjoy!
Note: Beef slices best when semi frozen. The thinner you cut the beef, the more tender it will be.