Cut 1 lbs of Sirloin beef into 1 inch thin strips. Wash the beef thoroughly and pat dry with paper towels.

Marinate the beef with half a tsp of salt, quarter tsp of black pepper powder, one tsp of garlic paste, one and a half tsp of ginger paste, two tbsp of brown sugar, one tsp of roasted sesame oil, one tbsp of olive oil or vegetable oil, three tbsp of cornstarch, and three tbsp of soy sauce. Mix all the ingredients together and let it sit for at least 30 minutes.

Cut one large onion into 1 inch cubes and one large bell pepper into 1 inch strips.

On medium high heat, add three tbsp of olive oil or vegetable oil to a large skillet. Wait until the oil is hot and add the beef strips. Do not overcrowd the pan and fry in batches. Fry for 4 – 5 minutes or until the beef is cooked through flipping the strips to make sure both sides are evenly browned. Remove from heat and place aside. Repeat the same on the next batch.

Once all of the batches are cooked, add the beef back into the skillet and pour the leftover marinate sauce and half a cup of water. Cook until the sauce is reduced, then place the beef aside.

Add one tbsp of olive oil or vegetable oil to the same skillet on medium high heat. Wait for the oil to turn hot, then add the onions. Cook for 1 minute, continuously stirring. Add the bell peppers and fry for another 2 minutes. Add half a tsp of garlic paste, half a tsp of salt, and a quarter tsp of black pepper powder.

Once the vegetables are tender, add the beef strips and mix together well. Remove from heat and serve.