For the Beef Braise: If using flanken-cut ribs, divide each strip into smaller pieces by slicing between the bones; if using English-cut ribs, leave as-is. Season beef all over with salt. In a large, heavy-bottomed pot or Dutch oven, heat half of the oil over medium-high heat until lightly smoking. Add half of the beef and cook, turning occasionally, until browned on all sides, about 8 minutes; transfer browned short ribs to a plate. Add remaining oil to pot and repeat browning process with the rest of the beef.

Return all beef to the pot, then add enough water to fully cover (about 2 to 3 quarts/liters) along with the coconut milk. Bring to a vigorous simmer and cook, stirring occasionally and adding more water as needed to keep beef submerged, until beef is fully tender and can be pierced easily with a paring knife, 2 1/2 to 3 hours. Remove pot from heat and set aside to cool, keeping beef submerged in cooking liquid, for at least 30 minutes. When cool, transfer beef to cutting board. Using a sharp knife, trim off and discard bones and cut beef into 1-inch pieces. Set aside, along with 1 cup (240ml) of beef cooking liquid and 2 tablespoons (30ml) rendered beef fat, which should have risen to surface of cooking liquid; remaining cooking liquid and fat can be refrigerated in an airtight container and saved for another use.

Meanwhile, for the Roasted Shallots: Place unpeeled shallots in a small, dry stainless steel or cast iron skillet and cook over medium heat, turning occasionally, until fully softened and blackened all over, about 30 minutes. Alternatively, you can grill the unpeeled shallots over low heat. Transfer shallots to a cutting board, allow to cool until comfortable to handle, then peel. Set aside.

For the Curry: Remove and discard the mid-rib from the makrut lime leaves; set half of the leaves aside. Stack remaining makrut lime leaves, fold in half widthwise, then slice into hair-thin strips; set aside separately.

In a 3-quart saucepan, combine reserved 2 tablespoons (30ml) rendered beef fat and 1/2 cup (120ml) coconut milk and bring to a simmer over medium heat. Cook, stirring often with a rubber spatula, until thickened slightly, about 3 minutes.

Add curry paste, stir vigorously to combine, and use rubber spatula to scrape the sides of the saucepan to fully incorporate the paste. Add the de-ribbed, whole lime leaves, and continue to cook, stirring and scraping constantly, until the fat begins to separate from the curry paste, about 3 minutes.

Add palm sugar and stir to melt. Continue to cook, stirring constantly, until color of paste deepens to a dark brick-red, about 30 seconds. Add fish sauce, tamarind, remaining 1/2 cup (120ml) coconut milk, and reserved 1 cup (240ml) beef cooking liquid, and stir until well incorporated. Add beef and shallots, and gently stir to incorporate into curry. Lower heat to medium-low to maintain a gentle simmer and cook, stirring occasionally and being careful not to break apart the beef, until curry has slightly reduced to a saucy consistency, about 10 minutes. Remove from heat, add sweet basil, and stir until wilted and incorporated.

Transfer curry to a large serving bowl or divide between individual bowls and top with remaining thinly-sliced lime leaves. Serve with cooked jasmine rice.