Split your Sichuan peppercorns into two equal piles. In a large heavy bottom pot, wok, or dutch oven, toast the first group dry over a medium-high heat just until fragrant, about 2 minutes. Remove from pot before they burn. Add in the vegetable oil and the other pile of peppercorns and cook 2 minutes or so to flavor the oil. Remove the peppercorns from the oil using a fork or slotted metal spoon and discard.
Meanwhile, grind the dry toasted peppercorns to a powder in a mortar and pestle or spice grinder.
Add the chicken to the oil and cook to brown, about 7 minutes. Add in the mushrooms and chile peppers and cook 5 minutes. Add in the ginger and garlic and cook 3 minutes.
Add in the broccoli, bean paste, xiaoxing wine, and soy sauce and cook 3 minutes, stirring the whole time. Add in the chicken stock. Bring to a simmer and allow to simmer about 10 minutes until the broccoli is tender. Taste for seasoning and add salt or soy sauce as needed.
Add in the tofu and gently stir so as not to break it up. Simmer 3 minutes.
Stir in some chile oil to taste, along with about half of the scallions and Sichuan pepper powder. Remove from heat.
Serve with additional scallions, Sichuan pepper powder, and chile oil for garnish.