In a medium saucepan over medium heat, melt the unsalted butter. Once foaming, add the all-purpose flour and whisk continuously for 1 to 1½ minutes to cook the flour (this creates a roux). Do not let it brown.

Slowly whisk in the whole milk and heavy cream, adding a little at a time until smooth. Continue whisking and bring the mixture to a gentle simmer (small bubbles at the edges) for 2 to 3 minutes; the sauce will thicken slightly.

Reduce heat to low. Add the cream cheese cubes and whisk until melted and smooth, about 1 to 2 minutes.

Stir in the shredded pepper jack and shredded sharp cheddar in batches. Add a handful (about ½ cup) at a time, stirring until each addition melts and the sauce is smooth before adding more. Keep the heat low to prevent the cheese from separating.

Once cheeses are incorporated, add the drained diced tomatoes with green chiles, ground cumin, garlic powder, kosher salt, and freshly ground black pepper. Stir to combine and heat through for 1 to 2 minutes. Taste and adjust seasoning if needed.

Stir in the chopped fresh cilantro and fresh lime juice. If using pickled jalapeños, stir them in now or reserve some for garnish. Keep the queso on the lowest heat or transfer to a small slow cooker set to warm or a heatproof serving bowl set over a very low bain-marie to keep it smooth and warm.

If the queso gets too thick while holding, whisk in 1 to 2 tablespoons of milk to loosen to desired consistency.

Chips & Garnish

Arrange the tortilla chips in a large shallow bowl or platter. For serving, place the warm queso in a heatproof bowl in the center or serve from the saucepan if kept warm on the stove using the lowest heat.

Sprinkle extra cilantro leaves and a few sliced pickled jalapeños over the queso for garnish. Serve with lime wedges on the side for guests to squeeze over chips as desired.

Encourage dipping with sturdy chips; refresh chips as needed to keep them crisp and avoid soggy pieces in the queso container.