Preheat the oven to 425 degrees F. Coat a large rimmed baking sheet with non-stick cooking spray.
In a large bowl toss together the potatoes, garlic, onion, green bell pepper, and red bell pepper. Add olive oil and melted butter and toss well to coat the potatoes and veggies. Add seasoned salt, cayenne pepper, and fresh ground black pepper, to taste.
Transfer to the prepared rimmed baking sheet and bake for 15 minutes. Use a spatula to toss and stir the potatoes and then spread them back out in an even layer and cook for an additional 15 minutes or until fork tender (time will vary based on of potatoes). Toss again and then raise the oven temperature to 500 degrees and bake until crisp and brown, an additional 10 to 15 minutes, tossing every 5 minutes.
Season to taste with salt and additional pepper if needed and serve.
Adapted from The Pioneer Woman