Combine the first 5 ingredients.
Pour 2/3 of the mixture into a Zip-Lock bag.
Add beef and shake until well combined.
Refrigerate 30 minutes.
Refrigerate remaining 1/3 marinade.
In a small bowl combine cornstarch and reserved marinade until smooth.
Set aside.
Remove marinated beef from refrigerator.
Remove beef and discard marinade.
Heat large skillet over medium to medium high heat with one to 2 tablespoons avocado oil.
Add beef and stir fry about 2-3 minutes until no longer pink.
Remove beef to separate plate and keep warm.
Add remaining avocado oil to skillet.
Add carrots and onions and stir fry about 5-6 minutes.
Add bell pepper and snow peas and stir fry 3 minutes longer, or until veggies are crisp-tender.
Stir cornstarch mixture into skillet.
Bring to a boil.
If sauce is too thick, add water slowly.
Cook and stir for about 2 minutes or until sauce is thickened.
Add beef and pineapple and heat through.
Serve over hot, cooked rice.