Put the grated cheddar in a saucepan and toss it with the cornstarch until every shred is coated and dusty.
Pour in the evaporated milk.
Set the pan over low heat and stir constantly until the cheese melts and the sauce turns smooth, glossy, and thick, about 5 minutes.
Serve warm.
Serve over certified gluten-free corn tortilla chips, steamed vegetables, or potato wedges. Season to taste — a pinch of salt, or a dash of hot sauce for grown-ups.