In a skillet over medium heat, brown the ground beef with diced onion for about 5-7 minutes. Drain excess fat.

Add garlic powder, salt, and pepper, then stir in ketchup and mustard until well combined. Remove from heat and let cool slightly.

Lay an egg roll wrapper in a diamond shape, place two tablespoons of the beef mixture near the bottom corner, then roll tightly while folding in the sides. Seal edges with water.

Heat oil in a deep pan for frying or preheat oven to 400°F (200°C) if baking.

Fry egg rolls until golden brown (about 3-5 minutes) or bake for approximately 15-20 minutes until crispy.

Serve hot with extra ketchup and mustard for dipping.