Heat oil in large skillet or wok over medium-high heat.
Add chopped, raw chicken and cook, stirring occasionally, until no longer pink.
Push cooked chicken to one side of the skillet.
Crack eggs into the other side of the skillet and scramble.
Add cooked rice, frozen mixed vegetables, soy sauce, and butter.
Stir all ingredients together and continue to cook until vegetables are heated through (5-7 minutes).
Top with sliced green onions.