Scrub potatoes and pat dry. Prick each one twice with the tip of a sharp knife. Arrange in the microwave in a circle. Microwave on high until tender, approximately 4 minutes, but will vary depending on microwave and size of the potatoes. (I use my automatic "Potato" setting.).
Line cookie sheet with foil (I prefer no-stick). Place cooked potatoes on cookie sheet and gently 'smash' by pressing down with the back of a spatula. Drizzle olive oil over them, turning to coat. Sprinkle with seasoning salt or salt and pepper to taste.
Roast at 400°F for 20-30 minutes until golden brown and crispy, depending on desired degree of doneness. Turning halfway through. Serve hot.
Note: it only takes about 20 minutes in my convection oven if I roast them while they are still hot from the microwave. If they have cooled, it takes longer.