Preheat oven to 450℉
Toss potatoes with olive oil. Bake potato slices on a baking sheet for about 15 minutes, turn over and bake another 15 - 20 minutes until golden and slightly crisp.
Next, overlap the potatoes in a cast-iron skillet that can be baked in the oven. Season potatoes with salt and pepper. Sprinkle with cheese and bacon. Bake for 5 minutes to melt cheese. Then sprinkle with scallions and cilantro.
In a separate dish, stir diced tomatoes (and jalapeño peppers if you like it hot) into the sour cream. Serve on the side as a dip.