To make the Chipotle Barbecue Sauce, combine the sugar, vinegar, tomato paste, sesame oil, molasses, soy sauce, and chile peppers in a small saucepan and bring to a boil. Reduce the heat to medium-low and simmer until it starts to become syrupy and dime-sized bubbles form, 12 to 15 minutes. Remove from the heat and allow to cool for at least 5 minutes. Transfer sauce to a blender or food processor, fill it no more than halfway, and place a towel over the top of the machine (when processed or blended, very hot liquids can explode.) Pulse a few times then process on high speed until smooth.

Salsa Fresca: In a mixing bowl combine the tomatillos, lime juice, red onion, cilantro, jalapeno, salt, and pepper, and mix thoroughly. Cover and refrigerate until ready to use.

Preheat a grill. Place the unopened oysters directly on the grill, and cook until they've opened their shells, about 2 to 3 minutes. Carefully spoon about a teaspoon of the Barbecue Glaze over the top of each oyster, and continue to grill for another 2 minutes, or until the shells are completely opened and the oysters are just cooked through. Spoon a teaspoon of the Salsa Fresca over the top of each oyster and serve immediately.