Zafra's Shrimp and Plantains with Chipotle Vanilla Chocolate Sauce: Camarones de Papantla con Vainil

Ingredients

• 1 1/2 pounds medium-size shrimp
• 2 plump Mexican vanilla beans
• 2 ripe plantains (should be soft with blackened skin or large patches of black)
• 1 cup safflower or corn oil for frying plantains
• 2 pounds plum tomatoes (or canned tomatoes, drained), peeled, seeded, and quartered
• 3 chipotles en adobo, or to taste
• 1/4 cup light olive oil or vegetable oil
• Salt
• 1 medium white onion, peeled and thinly julienned
• 1 tablespoon vanilla extract (if using an unsweetened extract, add 1 teaspoon light brown sugar)
• 2 ounces fruity dark chocolate (about 70 percent cacao content