Gaeng-rawaeng, curried away

Whole chicken thighs submerged in a deeply savoury golden curry redolent with spices. When the dish arrives on the table, flanked by impossibly flaky flatbread for sopping, you've got to be all in, tearing the juicy meat apart and swiping the bread through the rich and spicy sauce, table manners be damned. Thai food should be fiery but not burn you, and this dish demonstrates just that: A mix of green Thai chiles, serranos, and jalapeños yields just the right balance of heat. It is so delicious that if you make it at home to share, be warned: You'll be fighting for that last drop of curry sauce. If you ask most fans of Thai food in the West what their favorite curries are, they’ll probably rattle off a list pretty quickly—red, yellow, green, massaman, panang—because they’re so ubiquitous that they’ve become as familiar as pho or sushi. However, for many people, they also happen to be the only curries they know, because they’re the only ones offered by most Thai restaurants.
That’s a shame because there are countless kinds of curry in Thailand. There are curries that are popular throughout the country, like the ones listed above, but then there are others that like in many other countries are unique to a particular region, and there are even curries whose recipes are unique to specific families.
I don’t like to offer strict definitions for food, but what Thai people call gaeng, which translates roughly to curry, is a dish whose primary source of flavour is a prik gaeng, or a curry paste. The other defining feature of a gaeng is that it has a significant amount of liquid, ranging from completely soupy to just saucy.
A prik gaeng is simply a paste of ground up herbs and spices, the most important of which are the prik, or chillies.Gaeng can be one of themost humble, everyday dishes, but it can also be a part of a very fancy meal.
Even though the variations are endless, you can divide curries into two general categories based on what kind of liquid they use: coconut milk or water.This Gwaeng rawaeng uses the former.

Curry Paste
5 ounces assorted fresh green chiles (Thai chile, serrano, and/or jalapeño), seeded and chopped
¼ cup chopped lemongrass (from tender bottoms of 2 lemongrass stalks)
1 ounce fresh turmeric root, peeled and chopped (about 3 tablespoons), or 1/2 tablespoon ground turmeric
½ ounces fresh galangal, peeled and chopped (about 2 tablespoons)
4 fresh coriander roots or stems, chopped
¼ teaspoon coriander seeds
¼ teaspoon cumin seeds
¼ teaspoon ground cinnamon
⅛ teaspoon ground mace
½ whole star anise

Chicken
2 (13 1/2-ounce) cans coconut milk (not shaken or stirred)
¼ cup plus 1 tablespoon fish sauce (such as Red Boat), divided
1 3-pound whole chicken, wings tucked
1 lemongrass stalk, halved crosswise
2 teaspoons light brown sugar, or to taste
5 mini sweet peppers (about 4 1/2 ounces), seeded and cut lengthwise into ¼-inch-wide strips
½ cup loosely packed fresh Thai basil leaves or lemon basil leaves
Warm roti,or flatbreads for serving

Make the curry paste
Combine green chillies, lemongrass, turmeric, galangal, cilantro, coriander, cumin, cinnamon, mace, and star anise in a blender. Process until mixture is finely chopped and starts to form a paste, about 2 minutes, stopping to push mixture down using a plunger or lemongrass stalk as needed.

Make the chicken
Preheat oven to 375°F. Spoon out thick coconut cream from tops of coconut milk cans to measure 1 cup. Reserve remaining coconut milk in cans. Place thick coconut cream and curry paste in a 4- to 5-quart Dutch oven. Cook over medium, stirring constantly, until a layer of oil shimmers on top and mixture appears curdled, 8 to 10 minutes. Stir in 1/4 cup fish sauce. Add chicken, breast side up, and spoon curry mixture over top until chicken is well coated. Add reserved coconut milk to sauce around chicken; stir to combine. Bring to a simmer over medium. Cover Dutch oven, and transfer to preheated oven. Roast until chicken is tender and a thermometer inserted in thickest portion of thighs registers 155°F, 30 to 40 minutes, basting chicken with curry sauce once after 20 minutes.Insert tongs in chicken cavity; carefully remove chicken, and set aside on a large plate. Bring curry mixture to a boil over medium-high. Add lemongrass; cook, stirring occasionally, until sauce starts to reduce and thicken, about 5 minutes. Add brown sugar and remaining 1 tablespoon fish sauce; stir to combine. Add mini sweet peppers; return chicken to Dutch oven. Cook, stirring occasionally, until peppers soften slightly, about 3 minutes.Transfer chicken, curry sauce, and lemongrass to a deep serving platter. Sprinkle with basil, and serve with flatbreads.