• Dice the onion and green bell pepper into small, even pieces.
• In a large skillet over medium heat, combine the chopped vegetables and ground beef. Season with salt and pepper. Cook for 5–7 minutes, stirring occasionally, until the beef is browned and the onions are soft. Drain any excess grease.
• Stir in the Worcestershire sauce and flour, mixing until combined. Pour in the beef broth and simmer for about 3 minutes, or until the mixture thickens. Remove from heat and let cool slightly.
• Lay one egg roll wrapper in a diamond shape with a corner pointing toward you. Place half a slice of cheese in the center and top with 2 heaping tablespoons of the beef mixture. Fold the bottom corner over the filling, then fold in the sides. Roll tightly, sealing the top corner with a dab of water.

Air Fry:

• Brush oil onto both sides of the egg rolls, or mist with cooking spray. 
• Air fry ar 390 degrees for 12 minutes, flipping halfway through and checking for doneness at 10 minutes.

Bake:

• Preheat your oven to 425 degrees and line a baking tray with parchment paper.
• Lightly spray both sides of your egg rolls with cooking spray.
• Bake 10-15 minutes, turning halfway through, until crisp on both sides.

Pan Fry

• Add 1 quart of oil to a heavy bottomed skillet. Heat to 375 degrees F.
• Cook 4 egg rolls at a time for 2 to 3 minutes, or until golden brown and crispy, flipping once halfway through.
• Remove with tongs, being careful not to burn yourself, to a wire rack to let the extra oil drain.
• Repeat with remaining rolls.