Clams with Lemongrass and Chiles

Name: Clams with Lemongrass and Chiles
Ingredients: Coarse salt; 4 dozen small clams, such as littleneck, rinsed well (about 5 pounds); 2 stalks fresh lemongrass, hard outer leaves removed and reserved, bottom 4 inches of stalks, thinly sliced crosswise; 2 tablespoons vegetable oil; 2 shallots, thinly sliced (about 1/2 cup); 3 garlic cloves, minced; 2 small fresh green chiles, such as jalapeno, serrano, or Thai chiles, thinly sliced crosswise; 3 small fresh red chiles, such as cherry peppers or Holland chiles, thinly sliced crosswise; 1/2 cup lime juice, plus lime wedges, for garnish (5 limes total); 1/4 cup Asian fish sauce; 1 cup loosely packed fresh cilantro leaves, coarsely chopped