In a large stockpot over medium heat, add 2 tablespoons of canola oil and sweat the shallots, garlic and galangal. After about 1 ½ minutes, add the dried Thai bird peppers to bloom them. Add the lobster head and palm sugar.
When the aromatics have a little color on them, about 2-3 minutes total, add the clams, then the chicken stock. Bring to a simmer.
Cover the pot and cook until the clams open, about 10 minutes.
Meanwhile, make the herb salad:
In a medium bowl, combine the cilantro, mint, Thai basil, and bean sprouts. Toss with the juice of one lime and remaining canola oil and season to taste with salt and freshly ground black pepper.
Once the clams have opened, remove the lobster head and add the lobster claws, fish sauce, coconut milk, and the juice of 2 limes. Heat the ingredients through. Check and adjust the seasoning if necessary.
To plate: In a large bowl, add the rehydrated rice stick noodles, then, place the clams around the edge, ladling in the broth and lobster claws. Top with the herb salad. Drizzle with the hot chili oil and squeeze the remaining lime around the edge of the bowl. Serve immediately.