Salt the chicken. Pat the chicken dry. Rub with 2 tablespoons kosher salt all over, including inside the cavity. Let it sit while you get the pot ready. This seasons the meat and helps the skin.
Build the poaching pot. In a large pot, add the chicken, ginger, scallions, and smashed garlic. Add enough cold water to cover the chicken by about 1 inch. The exact amount will vary based on your pot and chicken size. Add the remaining 1/2 tablespoon salt.
Poach gently. Bring to a bare simmer over medium heat. As soon as you see steady small bubbles, reduce heat to low to maintain a gentle simmer. Skim foam for the first 10 minutes.
Cook until just done. Cover and keep the broth at a very gentle simmer for 35 to 45 minutes, depending on chicken size. If the chicken is not fully submerged, turn it once halfway through using tongs plus a wooden spoon for support, or gently hold it down with a small heatproof plate. The thickest part of the thigh should register 165°F. For especially juicy breast meat, you can pull the chicken when the breast hits about 160°F and let carryover finish before the ice bath stops the cooking.
Ice bath for great skin. While it cooks, fill a large bowl (or clean sink) with ice water. When chicken is done, carefully lift it out and lower it into the ice bath for 8 to 10 minutes. This stops carryover cooking and firms the skin. Remove and let it drain on a rack or cutting board.
Strain the broth and reserve chicken fat. Remove the chicken. Strain the poaching liquid into a clean pot or large bowl and discard the solids. Skim the golden fat from the surface into a small bowl (you want about 2 tablespoons for the rice). If the fat is hard to skim while warm, chill the broth briefly so the fat rises and firms up, then scoop it off. Taste the broth. It should be lightly salty and chicken-forward. If it tastes salty, dilute with a little water before using for rice. If it tastes flat, you can add a pinch more salt when cooking the rice.
Start the rice. Rinse 2 cups jasmine rice until the water runs mostly clear, then drain well. In a saucepan, heat 2 tablespoons chicken fat (or oil) over medium. Add minced garlic and grated ginger and cook 30 to 45 seconds until fragrant.
Toast, then simmer. Add rice and stir to coat for 1 minute. Add 2 1/2 cups reserved broth and 1/2 teaspoon salt (adjust based on how salty your broth is). Bring to a simmer, cover, and cook on low for 15 minutes. Turn off heat and let steam, covered, for 10 minutes. Fluff.
Make scallion-ginger oil. Put sliced scallions, grated ginger, and salt in a heatproof bowl. Heat 1/3 cup oil in a small saucepan until shimmering (not smoking). Carefully pour over the scallion mixture and stir. It should sizzle and smell incredible.
Make the chile sauce. In a small food processor or mortar, blend chiles, garlic, and ginger into a rough paste. Stir in lime juice, rice vinegar, broth, sugar, and salt. Adjust to taste. More lime for brightness, more sugar for balance, more broth to mellow heat.
Make the soy dip. Mix light soy, dark soy, and sesame oil. Add a splash of broth if you want it less intense.
Slice the chicken. Optional: rub the skin lightly with 1 tablespoon neutral oil for shine. Cut into serving pieces or slice boneless portions. Season lightly with a pinch of salt and white pepper if needed.
Warm and season the serving broth. Reheat some strained broth for serving. Taste and adjust with a pinch of salt if needed, plus a little white pepper. If you like, add a few sliced scallions.
Serve. Plate rice, chicken, and cucumber slices. Add a small bowl of warm broth on the side. Put all three sauces on the table and let everyone build their perfect bite.
