Prepare the ingredients: Grate cheddar cheese, chop jalapeños, slice sun-dried tomatoes, and slice black olives if needed.
Boil the potatoes: In a large pot, add baby potatoes and cover with water. Parboil for 15 minutes once boiling, then cool completely.
Preheat the oven: Preheat oven to 220 °C. Arrange cooled potatoes on a parchment-lined tray, skin-side down. Press down with a fork or glass. Top with cheddar cheese, jalapeños, black olives, and sprinkle with celery salt.
Bake in the oven: Bake for 15 minutes at 220 °C, then reduce to 140 °C for the last 15 minutes. Check every 15 minutes. Serve hot.