Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
Using a 1/4-cup measure, scoop portions of shredded cheddar onto the prepared sheet. Flatten each mound into a roughly 5-inch (12 cm) circle, leaving space between them (about 3 per sheet).
Bake for 6–8 minutes, until the edges are browned and the cheese is crispy while the center is slightly soft.
Remove from the oven and let cool on the sheet 2–3 minutes until just cool enough to handle.
Carefully lift each cheese round with a spatula and drape it over a wooden spoon handle, narrow rolling pin, or similar cylindrical object to form a taco shell. Hold until it begins to set.
Allow shells to cool completely so they harden, then fill as desired.