Elote Crema

In a medium bowl, combine the mayonnaise and Mexican crema. Whisk together until fully homogeneous — no streaks of either component should remain. Add the fresh lime juice a little at a time, whisking continuously; it will thin the mixture slightly and make it glossy. Add the chili powder and salt. Whisk vigorously for another 30 seconds. The crema should be smooth, glossy, and thick enough to cling to a spoon without running immediately. Taste at this point — the lime should be clearly present, the chili should give warmth rather than heat, and the overall flavor should be creamy, tangy, and moreish.

Fold half of the crumbled cotija into the crema base and stir to combine — the salt from the cotija will further season the sauce. Taste again and adjust if needed. Transfer to a shallow bowl for dipping whole cobs, or to a squeeze bottle for esquites (corn cups). Just before serving, dust the surface generously with extra chili powder or Tajín and scatter the remaining cotija. The sauce can be made up to 3 days ahead and refrigerated; the flavors improve overnight as the lime mellows and the chili blooms.