Soak the dried shiitake mushrooms in 1.5 cups of warm water for at least 20 minutes until fully softened. Remove the mushrooms, squeeze out the excess liquid back into the bowl, and strain the soaking liquid through a Sieve — you'll use 1 cup of this deeply flavored liquid later. Remove and discard the stems; halve the caps.

In a Mixing Bowl, whisk together the 3 tbsp salsa de soja, 1 tbsp salsa de ostras, Shaoxing wine, 1 tsp aceite de sésamo, 1 tsp azúcar, ½ tsp pimienta blanca, and 1 tbsp almidón de maíz until smooth. Add the 2 lb muslos de pollo con hueso y piel, cortados en trozos de 2 pulgadas a través del hueso, o dejar enteros and toss well to coat every piece thoroughly. Let marinate at room temperature for at least 15 minutes, or cover and refrigerate for up to 4 hours for deeper flavor.

Heat a Dutch Oven over medium-high heat. Add the 2 tbsp aceite neutro como vegetal o canola and heat until shimmering. Working in a single layer (in batches if needed), sear the 2 lb muslos de pollo con hueso y piel, cortados en trozos de 2 pulgadas a través del hueso, o dejar enteros skin-side down for 3–4 minutes until golden brown. Flip and sear the other side for 2 minutes. Transfer the chicken to a plate — it won't be cooked through yet. Don't discard any marinade left in the bowl.

Reduce the heat to medium. In the same Pot, add the 5 dientes de ajo aplastados y picados aproximadamente, 1 piece jengibre fresco, trozo de 2 pulgadas, pelado y cortado en monedas finas, and the white parts of the 3 tallos de cebollas verdes partes blancas y verdes separadas, cortadas en trozos de 2 pulgadas. Stir-fry for about 1 minute until fragrant and just starting to turn golden.

Add the soaked shiitake mushrooms and stir to combine with the aromatics. Cook for 1 minute.

Pour in the strained mushroom soaking liquid, ½ cup caldo de pollo, 3 tbsp salsa de soja, 1 tbsp salsa de ostras, and 1 tsp azúcar. Stir to combine, scraping up any browned bits from the bottom of the Pot — that's all flavor. Pour in any remaining marinade from the Mixing Bowl.

Nestle the seared 2 lb muslos de pollo con hueso y piel, cortados en trozos de 2 pulgadas a través del hueso, o dejar enteros back into the Pot, skin-side up, in a single layer if possible. Bring the liquid to a boil, then reduce the heat to low. Cover tightly with the lid and braise for 30–35 minutes, until the chicken is completely cooked through and very tender. Check once halfway through — if the liquid looks too low, add a splash of 2 tbsp agua fría or stock.

In a Mixing Bowl, mix together the 1 tbsp almidón de maíz and 2 tbsp agua fría until smooth to make a slurry. Increase the heat to medium, push the chicken to one side, and stir the slurry into the simmering sauce. Stir gently and cook for 1–2 minutes until the sauce thickens to a glossy, gravy-like consistency that coats the back of a spoon.

Remove the pot from heat. Scatter the sliced 3 tallos de cebollas verdes partes blancas y verdes separadas, cortadas en trozos de 2 pulgadas green tops over the chicken and drizzle with a little 1 tsp aceite de sésamo if desired. Serve directly from the Dutch Oven with plenty of steamed jasmine rice to soak up the sauce.