Heat a large skillet or wok over medium-high heat.
Heat vegetable oil and add onions. Cook, stirring often, until soft and translucent; about 3-4 minutes. Add vegetables and cook until tender; about 2-3 minutes. Stir in garlic and cook for about a minute.
Stir in rice, green onions, pineapple, bacon, soy sauce and black pepper. Cook, stirring constantly, until heated through; about 2 minutes.