Prepare rice separately.
Place filet mignon tips in medium bowl with kosher salt, black pepper, Chinese five spice, garlic powder, smoked paprika, and 1 tablespoon of cornstarch; toss thoroughly until well incorporated.
Dredge filet mignon tips in 1/4 cup cornstarch on all sides.
In a wok, add 1/2 cup grapeseed oil and 1 teaspoon sesame oil; bring to medium-high heat.
Sauté and cook filet mignon tips in small batches to not overcrowd the wok; brown on both sides, about 3-4 minutes each side.
Remove browned tips from wok and place on paper towel-lined plate.
Wipe out wok and add 1/4 cup grapeseed oil; return to medium-high heat and add all vegetables and a pinch of salt and pepper.
Sauté vegetables until tender, but still al dente, about 1 minute.
Add stir-fry sauce to wok and bring to a boil until thickened; add browned tips and cilantro back into wok and toss until coated.
Season to taste with salt and pepper.
Serve over steamed white or brown rice.