How to Make It
Preheat oven to 425°. Prick potatoes all over with a fork, then rub with oil and sprinkle with salt and pepper. Wrap each in foil.
Put potatoes on a baking sheet and roast until a fork slides in without resistance, about 1 hour.
Carefully unwrap each potato, then score a large oval into top of potato with a sharp knife, almost to edges of potato. With a grapefruit spoon or soup spoon, dig into potato to remove about a third of it; save the cooked potato for another use, such as potato pancakes.
With a fork, fluff up remaining inside of potato (this helps toppings permeate the potato), leaving about 1/4 in. of firm potato "shell." Top with your choice of topping combinations. If you like, put potatoes back in oven for a few minutes to heat or melt toppings. Serve any extra topping on the side.
*Unlike Spanish chorizo, which is firm and cooked, Mexican chorizo is soft and raw, and must be cooked before eating; squeeze it from its casing and sauté over medium-high heat until broken up into small bits and well browned, 10 to 12 minutes. Find good-quality Mexican chorizo at Latino markets--which is where you'll also find queso fresco (fresh cheese) and crema (Mexican-style sour cream).
Note: Nutritional analysis is per potato, without toppings.