Preparation

Make the curry paste

• Combine the lemongrass, chiles, oil, shallot, garlic, ginger, cilantro, coriander, cumin, and lime zest in a blender. Add 3 Tbs. water, 1/2 tsp. salt, and 1/8 tsp. pepper, and blend to form a coarse, wet paste.

Make the curry

• In a 4-quart saucepan, cook the curry paste over medium heat, stirring frequently, until much drier and just beginning to stick to the pan, about 4 minutes. Add the coconut milk, broth, 1/2 cup water, and the sugar. Increase the heat to medium high, bring to a boil, reduce to a simmer, and cook, stirring occasionally, for 5 minutes. Add the carrots and snap peas, bring to a simmer, and cook until just barely tender, about 4 minutes. Stir in the fish sauce, and season to taste with salt.
• Pat the scallops dry. Heat a large cast-iron or other heavy-duty skillet over medium-high heat until very hot. Add the remaining 1 Tbs. oil and the butter. Sprinkle the scallops all over with coriander and ¼ tsp. salt. Working in batches if necessary to keep from crowding, cook the scallops, undisturbed, until very well browned on one side, 2 to 3 minutes. Flip and cook until just barely cooked through, 2 to 4 minutes more, depending on size. Transfer to a plate. Repeat, if necessary, wiping out the pan and adding more butter and oil as needed.
• 搅拌切碎的香草咖喱。服务在rice or noodles, if you like. Top the curry with the scallops.

Make Ahead Tips

The curry paste can be stored covered and refrigerated, for up to 5 days.