In a large bowl, combine the cornstarch, salt, and pepper.
Add the beef strips and coat generously with the seasoned cornstarch. Set this aside.
In a wok, large skillet, or sauté pan over medium-high heat, warm the oil. Add the pepper flakes and dried chilis. Sauté until fragrant and toasted, approximately 30 seconds.
Stir in the garlic and ginger. Cook until the garlic starts to soften, about 1 minute.
Add the bell peppers and scallions and continue to cook until they start to soften and get a little color, again about 1 minute.
Add the beef and cook this until it is just browned, approximately 1-1/2 minutes, stirring often.
Give the sauce another whisk to combine and add it to the beef in the pan. Cook until it bubbles and reduces. It will stick to and coat the beef. This will take another minute or two.
Stir in the peanuts. Remove the pan from the heat and add the basil to the pan.
Serve immediately with rice.