penne with stir-fried beef and red bell pepper

Why I Love This Recipe
my grandmother got this from Gourmet 1993 page 150.
my dad makes this to perfection.
Ingredients You'll Need
2 tablespoons of cornstarch
1/4 cup soy sauce
1 1/2 cup of beef broth
2 tablespoons of scotch
1 tablespoon of sugar
1 teaspoon of sesame oil
3 tablespoons vegetable oil
1 lb boneless sirloin cut into strips
2 red bell peppers cut into strips
2 large garlic cloves minced
6 scallions sliced thinly for small rings
1 teaspoon of dried hot red pepper flakes ( i dont use)
1 lb of penne
Directions
In a bowl wisk together the corn starch, soy sauce, beef broth, scotch, sugar, and sesame oil.
In a large heavy skillet or a wok, heat 1 tablespoon of the vegetable oil over high heat and stir fry beef patted dry in 2 batches for 30 seconds or until brown on outside and pink inside.
Then heat the remaining oil in skillet without beef on a lower heat and add bell peppers for 2 minutes and then transfer them to a bowl with the beef.
Then fry garlic quickly and stir the cornstarch mixture and add it to the skillet.
Cook sauce stirring until it thickens and then stir in beef, scallions ( red pepper flakes if wanted) and salt to taste.
Then add in cooked penne, drain well and mix together.