Grab a large skillet and cook your ground beef or turkey over medium heat. Add the finely chopped onion and cook until the meat is browned and the onion is soft and translucent, about 5-7 minutes.

Drain off all the excess grease. You can tilt the pan and spoon it out, or transfer the meat mixture to a colander lined with paper towels.

Once the grease is drained, put the meat mixture back in the skillet (off the heat) or in a medium bowl. Stir in the shredded cheddar cheese, ketchup, yellow mustard, and Worcestershire sauce. Mix everything together until the cheese is starting to melt from the residual heat and everything is well combined. Give it a little taste and add salt and pepper if needed. The filling is ready!

Get out your egg roll wrappers. Carefully separate them – they can stick together! Cover the stack with a damp paper towel while you work to keep them from drying out. Set out a small bowl with your beaten egg (this is your egg wash) and a plate or baking sheet for the finished, un-fried egg rolls.

Place an egg roll wrapper on a clean, dry surface with one corner pointing towards you (like a diamond). Put about 2-3 tablespoons of the filling just below the center of the wrapper. Don't overstuff it!

Fold the bottom corner up over the filling and tuck it in tightly.

Fold the left and right corners towards the center, overlapping slightly like an envelope.

Now, starting from the bottom, roll the wrapper tightly upwards. Before you reach the top corner, dip your fingers in the egg wash and moisten that top corner.

Finish rolling all the way up, using the egg wash to seal the roll. Press gently to make sure it's sealed well. Place the rolled egg roll on your prepared plate or baking sheet and repeat with the remaining filling and wrappers.

Pour about 1-2 inches of vegetable oil into a heavy-bottomed pot or Dutch oven. Heat the oil over medium-high heat to about 350-375°F (175-190°C).

Carefully place 3-4 egg rolls into the hot oil at a time, being careful not to overcrowd the pot. Fry for 2-3 minutes per side, or until they are a beautiful golden brown and crispy all over. Use tongs to carefully flip them.

Once golden, use tongs to remove the egg rolls from the oil and place them on a wire rack set over a paper towel-lined plate to drain any excess oil. Repeat with the remaining egg rolls.

Let them cool for just a couple of minutes and serve them up with your favorite dipping sauces.