Place potatoes in a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low, cover, and simmer 10 minutes. Drain. Cool, then cut into a 1/2-inch dice.

Combine potatoes, onion, and bell peppers in a bowl; drizzle in vegetable oil and gently stir until evenly coated. Transfer mixture to resealable plastic freezer bags; store in the freezer.

To prepare, cook frozen potato mixture in a nonstick skillet over medium-high heat until crispy and golden brown, stirring occasionally, about 20 minutes.