Step 1

Slice the jalapeños and onions. 6 slices of jalapeño is about half a small jalapeño. You can slice and add the whole thing if you want your sauce to have a little kick to it. You need 3/4 cup onions, which is about 1 very small onion or half a medium onion.

Step 2

Set a medium frying pan over medium high heat. When hot, add 1 tablespoon oil. It should shimmer right away. Add the sliced jalapeño, sliced onion, and 2 tablespoons peppercorn.

Step 3

Sprinkle with 1 and 1/2 teaspoons kosher salt and saute for 3-5 minutes.

Step 4

Add 1 tablespoon white wine vinegar and 2 tablespoons white wine (I used cooking wine).

Step 5

Continue sautéing until the liquid has mostly evaporated and absorbed into the onions and jalapeños.

Step 6

Add 2 cups cream and stir it together. After about 30 seconds, when the cream is warm but not starting to bubble, remove from heat.

Step 7

Set aside and let steep for 30 minutes.

Step 8

Chop 2 cups of American cheese while you wait. (2 cups is 8 ounces.) Shred 2 cups of cheddar cheese. Set aside.

Step 9

After 30 minutes, use a sieve to strain out the jalapeños, onions, and peppercorns. Add the smooth cream back into the pan you were using. You don't need to clean the pan, but make sure you've scraped out all the solids.

Step 10

Set the pan of smooth cream back over medium heat and stir occasionally. When the mixture starts to get frothy on the edges and form small bubbles, add the American cheese and Cheddar cheese in increments, stirring with a whisk as you go. Turn the heat down to low.

Step 11

Continue whisking until the mixture is completely smooth.

Step 12

Serve immediately while hot! If your cheese starts to thicken, heat again on low and stir in milk a tablespoon at a time to thin it to the consistency you like.

Step 13

Cheese sauce should be stored covered in the fridge. It will solidify when chilled. To reheat, place back in a saucepan and set over low heat for several minutes, whisking frequently. Add milk a tablespoon or two at a time until it is thinned out to the consistency you want. You can do this in the microwave too, just make sure you only heat in short increments, stirring in between.