How to Make It
Light a grill. In a medium saucepan, heat the olive oil until shimmering. Add the shallots, garlic and a generous pinch of salt and cook over moderate heat, stirring, until softened, about 5 minutes. Add the tomatoes, wine, thyme leaves, chipotle and sauce and cook, stirring, until just bubbling, 3 minutes. Remove from the heat.
Arrange a 3-foot-long double-layer sheet of heavy-duty foil on a work surface. Lay a 2-foot-long sheet of parchment paper on top. Pull up the foil on all sides to form a cup. Spoon half the tomato mixture into the packet and pile the mussels on top. Spoon the remaining tomato mixture over the mussels and add the thyme sprigs. Fold the foil up over the mussels, leaving as much space as possible for them to open, then pinch the edges to seal tightly.
Carefully slide the foil packet onto the grill, close the lid and cook over high heat until the mussels open, about 20 minutes; discard any mussels that don’t open. Discard the thyme sprigs. Transfer the mussels and all the juices to a serving bowl and garnish with parsley. Serve with crusty bread.