Preheat the oven to 400°F (200°C) and place a rack in the center position.
Line a baking sheet with parchment paper.
Divide the 1 cup shredded cheese into four equal portions (1/4 cup each). Place each portion on the prepared parchment, spaced at least 2 inches apart. Gently press each portion down with the back of a spoon or a measuring cup to form a thin, even circle.
Bake on the center rack until the cheese is bubbly and the edges are lightly browned, about 6–8 minutes. Watch closely so it does not burn.
Remove the baking sheet from the oven and let the cheese circles cool on the parchment for 1–2 minutes so they firm up slightly but are still pliable. Use caution: they will be very hot.
Using a thin spatula or your hands (with oven mitts), carefully lift one cheese circle off the parchment and immediately drape it over a curved surface (for example, a rolling pin, bottle, or the edge of a heatproof bowl) to form a taco shape. Repeat with the remaining circles.
Let the shaped cheese shells cool completely until they are crisp and hold their shape, then enjoy.