In a medium saucepan over medium heat, melt the unsalted butter. When it foams, add the all-purpose flour and whisk constantly for 1 to 2 minutes until the mixture is golden and smells slightly nutty — this cooks out the raw flour taste.

Add milk

Slowly pour in the whole milk while whisking constantly to avoid lumps. Continue whisking and bring the mixture to a gentle simmer (small bubbles around the edge). Cook 3 to 4 minutes until the sauce has thickened enough to coat the back of a spoon.

Soften cream cheese

Reduce heat to low and add the cream cheese in small pieces, whisking until fully incorporated and smooth.

Season

Whisk in the Worcestershire sauce, Dijon mustard, garlic powder, onion powder, smoked paprika, cayenne, kosher salt, and black pepper until evenly distributed. Taste and adjust salt or cayenne as needed.

Add cheeses

Remove the saucepan from the heat. Add the grated cheeses in two additions, stirring after each addition until melted and smooth. Do not return to high heat once the cheese is added, as that can make the sauce grainy. If the sauce is too thick, add up to 1/4 cup (60 ml) more milk, 1 tablespoon at a time, stirring to reach desired consistency.

Mix-ins & Finish

Fold in the sliced green onions and chopped pickled jalapeños. If using, stir in the chopped crispy bacon and chopped cilantro, reserving a small amount for garnish.

Transfer the Bronco Cheese to a warm serving bowl. Garnish with the reserved green onions, cilantro, and a few extra jalapeño slices. Serve immediately with lime wedges on the side for diners to squeeze over their serving.

Storage and reheating: Cool completely, then refrigerate in an airtight container up to 4 days. Reheat gently over low heat on the stovetop, stirring frequently; if sauce has thickened, stir in a splash of milk to loosen. Alternatively reheat in a double boiler or in short intervals in a microwave, stirring between intervals.