Shrimp in Chile Sauce

This lusty dish is adapted from the wonderful chile shrimp served at one of my favorite Isthmian restaurants, Bar Jardín in Juchitán. Odilia Román, the chef, makes a related but differently seasoned dish with crabs, Jaibas en Chile Chipotle.

For the right flavor, use whole unpeeled shrimp with the heads on. In this country shrimp are almost always frozen before they get to the retailer and sold without the heads. You have to beg a fishmonger to sel