Heat a wok or large, deep skillet over medium-high heat and add a teaspoon of olive oil.
Whisk in the eggs and cook, stirring often, until set. Transfer to a plate.
Add another tablespoon of olive oil to the skillet. Add onion and cook until translucent; about 2 minutes, stirring often to avoid burning. Stir in garlic, then add frozen vegetables and cook until heated through. Season with a pinch of salt.
Soften the butter in the center of the skillet, then add cold rice to the skillet and stir
To combine with the vegetables. Press down into the pan to brown the rice lightly for a couple of minutes - you'll hearing popping and sizzling and that's what you want - then stir and repeat a few times. It's ok if the rice is chunky; it will break up a bit as it warms.
Return the egg to the skillet and stir to heat through.
Remove from heat, then stir in 1-2 tablespoons of soy sauce. Use more or less based on your liking.
Garnish with sliced green onions and serve immediately.
