Heat the oil in a Dutch oven over medium heat. Sweat the shallots until translucent and without any color, 1 to 2 minutes, and then add the garlic and cook 1 minute longer. Pour in the wine and bring to a simmer before adding the mussels. Cover tightly with a lid and steam until the mussels open, 3 to 4 minutes. Remove the mussels from the pot to avoid over-cooking, and discard any that do not open. Serve alongside the cooking liquid.