1 tablespoon coriander seeds, toasted and coarsely ground
1/4 cup fresh lime juice (from 2 to 3 limes)
4 ounces cream cheese, room temperature
1/2 cup sour cream
Cayenne pepper, for sprinkling
Cut-up cucumbers, jicama, and radishes, or chips, for serving
Heat oil in a large skillet over medium heat. Add onion, chiles, coriander, and 1 teaspoon salt. Saute, stirring occasionally, until onion and chiles are tender and caramelized, 25 to 30 minutes. Let cool completely.
Stir together lime juice, cream cheese, and sour cream in a large bowl, using a rubber spatula, until smooth. Stir in onion mixture. Season with salt if necessary. Refrigerate at least 1 hour and up to 1 day. Sprinkle with cayenne. Serve with cut-up vegetables or chips.