Press the tofu cubes and then marinate in a thin layer of peanut oil overnight, flipping once.
Heat about a teaspoon of peanut oil in a small saute pan over medium heat. Add half of the sliced shallots and saute until crispy. Remove from the pan and lower the heat to medium-low. Add a bit more oil to the pan and add in the remaining shallots to slightly soften, about two minutes.
Add in the garlic, galangal and lemongrass and scallions and saute for about 2 minutes more. Remove from the heat and stir in the chopped cilantro.
Grill or saute the tofu and let it cool slightly. To hollow out the tofu, cut a deep X in one of the narrow sides. I used a grapefruit spoon to scoop out about 1/3 of the tofu inside, but a regular spoon would also work.
Using a small spoon or your fingers, gently stuff the tofu pieces with the lemongrass-cilantro mixture, spooning any of the remaining mixture over the top.
Top everything off with the crispy shallots and red pepper flakes and serve with a soy-vinegar or dumpling sauce.