home fries recipe

4 large russet potatoes, peeled and diced into 1/2-inch cubes - 1 large onion, diced - 1 red bell pepper, diced - 1 green bell pepper, diced - 2 tablespoons olive oil or vegetable oil - 1 teaspoon garlic powder - 1 teaspoon paprika - Salt and black pepper to taste - Fresh parsley, chopped (for garnish, optional)