8 fresh long red chiles, such as Holland, seeded and coarsely chopped
5 small dried red chiles, such as chiles de árbol, seeded
2 stalks of fresh lemongrass, tender inner white bulbs only, thinly sliced
3 garlic cloves, coarsely chopped
3 small shallots, coarsely chopped, plus 4 medium shallots, thinly sliced
1 tablespoon water
1/2 cup plus 1 tablespoon vegetable oil
4 whole chicken legs, split into legs and thighs (3 pounds)
Kosher salt
One 14-ounce can unsweetened coconut milk
2 tablespoons fresh lemon juice
Freshly ground pepper