Slowly pour in 2 cups of milk, a few splashes at a time at first, whisking constantly so no lumps form. Continue whisking over medium-high heat for 4–6 minutes, until the mixture thickens enough to coat the back of a spoon.

Once the base is thickened and no longer boiling hard, remove the pot from the heat (or drop it to the lowest setting) and add 3 cups of freshly shredded sharp cheddar cheese a handful at a time. Whisk each addition until fully melted before adding more — taking the pot off direct heat matters here, since cheese heated above about 160°F can tighten up and separate into a grainy, oily sauce instead of staying glossy.

Whisk in ¼ teaspoon granulated garlic, 1–2 tablespoons buffalo hot sauce, and ½ teaspoon salt, then taste and add more salt if needed since cheddar and hot sauce both vary in saltiness. The sauce is ready when it's glossy and thick enough to cling to a spoon; if it feels too thick, whisk in a little warm milk until it loosens back up.