Yummy beef stir fry

This is a beef stir fry I made at a dinner a party a couple of months ago and it was a big hit.

1 lb sirlong steak, trimmed of fat, thinly sliced (I've used other types of steak and it worked just as well)

Marinade:
3 tbsp asian fish sauce
2 tbsp reduced sodium soya sauce
1 tbsp brown sugar
1 tbsp grated gingerroot
1 tsp minced garlic
1/2 tsp red pepper falkes

1 tbsp peanut or canola oil
1 large red pepper, cut into strips
1 medium red onion
Lots of fresh basil leaves (at least 20)

Place steak spices in a bowl. Whisk together marinade. Pour over steak and let sit for 30 minutes at room temperature.

Heat oil over medium high heat. Remove steak from marinade, shaking off the excess liquid. Reserve marinade.
Cook steak until just cooked through and transfer to a bowl. Add onion and peppers and cook for about 5 minutes until veg are tender. Return beef to wok and add basil and reserved marinade. Cook 2 more minute until basil leaves are wilted and beef is hot.

I add extra veg, green pepper, bamboo shoots, etc.

We serve it over rice and for 4 servings over a cup of rice we figured this is 9 points.