Grilled Prawns With Tom Yum Sauce

Make the sauce. Heat a medium saucepan over medium heat. Add the shrimp heads and cook, stirring, until aromatic, 3 to 5 minutes. Add the lemongrass, galangal, makrut lime leaves and bird’s eye chile and cook, stirring until fragrant, about 5 minutes. Add chile paste, salt and cream. Increase heat to high and bring to a boil. Reduce heat to medium low and simmer until the flavors have melded, 30 to 40 minutes. Add the cornstarch and water mixture and stir until the sauce coats the back of a spoon. Strain through a fine sieve, pressing the solids to extract as much of the liquid as possible. Discard the solids and stir the sauce to blend completely. Makes about 1 1/2 cups of sauce.

Butterfly the prawns: Place a prawn on its back and with sharp kitchen scissors snip the shell lengthwise down the center between the legs and all the way to the head. With a sharp knife, gently cut down through the incision without cutting through the shell to open up the prawn like a book. Using the tip of the knife, gently nudge the intestinal tract and then use your fingers to pull it out and remove it. Repeat with remaining prawns.

Grill the prawns: Put the butterflied prawns on a medium-heat grill shell-side down and cook until the shells have changed to a bright pink color, 2 to 4 minutes. Remove the prawns from the grill to a rimmed baking pan, brush with melted butter and finish cooking in a 350 degree oven, about 2 minutes, depending on the size of the prawns.

To serve, drizzle a few teaspoons of the sauce over each prawn and garnish with fresh cilantro leaves.