1. Preheat the oven to 450 degrees.
2. Wash the potatoes then cut into 1 1/2" chunks and place in an ovenproof pan. I use a 1/2 chafer pan because it fits so well in the oven. This is the same size as the common 9 x 13 pan you probably have hangin' around your kitchen.
3. Add the butter to the potatoes, then place the pan into the oven for about 10 minutes to melt the butter.
4. Take the pan out of the oven, after the butter is melted., and stir it up well with a spatula until you've got all the potatoes coated with the butter. Add the Kosher Salt, Black Pepper, Garlic, and Blacken, and mix well, until all of the potatoes are coated with the spices.
5. Return to the oven and bake for a total time of 1 1/2 hours, stirring them up every 1/2 hour or so. After an hour, you'll notice that they've gotten soft. You could eat them like this, but they're much better when they've cooked the extra half hour, because they'll get crunchy on the outside, while remaining soft textured in the middle.