Preheat the oven to 220 degrees C.
In a large bowl, toss together the potatoes, garlic, onion, green bell pepper, red bell pepper, olive oil, butter, seasoned salt, cayenne pepper and some kosher salt and pepper.
Bake for 20 to 25 minutes, shaking the pan twice.
Raise the heat to 260 degrees and bake until crisp and brown, 10 to 15 minutes.
Sprinkle with a little more salt and pepper before serving.