Grilled corn and potato salad

2 tablespoons mayonnaise;

2 tablespoons sour cream;

2 tablespoons fresh lime juice;

1 teaspoon kosher salt;

1 teaspoon ground ancho chile or chili powder;

1⁄2 teaspoon smoked paprika (pimentón), plus more for sprinkling;

1⁄8 teaspoon cayenne pepper;

1 pound small, waxy potatoes (such as Red Bliss or creamers), halved or quartered;

2 tablespoons vegetable oil;

4 to 6 ears freshly shucked corn, silks wiped away with a damp towel;

1⁄4 cup chopped scallions (white and tender green parts);

2 tablespoons finely chopped flat-leaf parsley;

1⁄4 cup freshly grated queso Cotija or Parmesan cheese.

Preheat the grill to medium high.
Whisk together the mayonnaise, sour cream, lime juice, salt, ground chile, smoked paprika, and cayenne in a large bowl.
Place the potatoes in a large saucepan and cover with cold water. Add 1⁄2 teaspoon kosher salt per cup of water. Bring to a boil, reduce the heat, and simmer until the potatoes are barely tender, about 8 minutes. Don’t cook them too long or they’ll get too mushy to grill. Drain the potatoes well, transfer into a large bowl, and let steam dry for 2 minutes. Drizzle the oil over the potatoes and toss to coat. Grill the potatoes in a mesh grill basket until nicely browned and cooked through, about 8 minutes.
Place the ears of corn directly on the grill grate. Cook the ears, turning them with tongs as needed, until most of the kernels are browned and a few are lightly charred, about 12 minutes. Set the corn aside until cool enough to handle.
Pour the hot potatoes into the bowl with the mayonnaise mixture and stir gently to coat. Cut the kernels from the cobs and add to the potato mixture. Stir in the scallions, parsley, and cheese. Check the seasoning.
Sprinkle with more smoked paprika and serve warm or at room temperature.