Heat a non-stick skillet over medium-high heat. Add the oil, onion then pepper. Cook for a few minutes while you cube the potato. Add the potato. Liberally sprinkle with kosher salt and a bit of pepper. Cover.
1 teaspoon olive oil, thick slice of sweet onion chopped, 1 medium-large sized baking potato, kosher salt & pepper, medium bell pepper chopped
Now. LEAVE IT ALONE for 3 minutes. Sorry, didn't mean to scream but this is the key. We want to just about burn the side that's down. After 3 minutes toss and assess the burnt-ness. If is too black then you may want to lower to medium. I kept the heat at medium-high but I was going for the scorched look. Re-cover and leave alone for another 3 minutes.
After the second three minutes, toss again and give a potato a try. It should be getting soft. If you'd like to add more seasoning do so now.
Cover and cook for an additional 3 minutes. This should be long enough to cook the cubed potatoes. If it isn't, repeat the process until they are to your liking or simply lower the heat to medium-low and keep the cover on until you are ready to eat.