Bring large pot of water to a rolling boil.
Season with salt until salty like the sea. Add beans and blanch 1 minute, or until just barely cooked through. If you are cooking beans immediately afterwards, blanch, drain, and let cool. If you are cooking beans hours or days in advance, blanch, shock in ice water, drain, and reserve in refrigerator.
Grind all spices in spice grinder until coarsely ground.
Heat wok, large cast iron skillet, or other heavy-bottomed pan on high heat until smoking. Add oil and let heat 30 seconds.
Add pork belly with spices and sauté 2–3 minutes, or until lightly browned and outsides are beginning to crisp up.
Add Shaoxing wine. If using a wok, drizzle on outer rims for it to sizzle and caramelize in the process.
Add a splash of soy sauce, following a similar pattern as the Shaoxing wine.
Move pork belly aside in wok. Add garlic, shallot, ginger, and serrano peppers to center of wok. Sauté in peanut oil and pork belly fat 1–2 minutes until fragrant, then stir to combine with pork belly.
Add beans and bean sauce to wok. Sauté another 3–4 minutes, or until beans are cooked through, while adjusting to taste with soy sauce, mirin, sugar, fish sauce, white pepper.
Once beans are cooked through, remove from heat and stir in sesame oil.