Lemongrass Beef for Spring Rolls

1 lbs beef chuck tenderloin, ribeye, sirloin, or center round (slice thinly against the grain into bite-size pieces)
1/4 cup minced lemongrass
3 garlic cloves peel and finely chop
1/2 yellow onion peel and cut into thin wedges
3 tbs oyster sauce
1 tbs regular soy sauce
3 tbs granulated sugar
2 tbs orange juice
1 tbs sesame oil
2 tsp red pepper flakes

In a large mixing bowl, combine lemongrass, garlic, onion, oyster sauce, soy sauce, sugar, orange juice, sesame oil, and optional red pepper flakes.
Add sliced beef and marinate for at least 30 minutes or overnight in the fridge for better results.
It is best to cook the beef outside using a portable butane burner and a grill plate. Heat up the griddle and melt a tablespoon of butter at a time. Add a portion of beef and quickly grill for 2-3 minutes.