Toss shrimp or chicken with 3 drops sesame oil and ½ teaspoon soy sauce. Set aside.
Heat a large non-stick wok or skillet to high heat. Add 2 tablespoons oil.
Add the yellow onion, bell pepper, peas and carrots to the pan and stir fry for 3-4 minutes until they start to soften.
Add in chicken or shrimp. Stir-fry until shrimp or chicken is cooked through.
Stir in minced garlic and chopped green onions.
Push vegetables and shrimp or chicken to the side of the pan and add in beaten eggs. Scramble until cooked then stir to combine the eggs with the vegetables and protein.
Add cold rice.
Stir in oyster sauce and soy sauce. Stir to combine.
Adjust seasonings with salt, pepper, and/or additional oyster sauce and soy sauce.
Stir-fry for 4-5 minutes longer, then serve hot.