Peanuts: If you're using raw/untoasted peanuts, you can quickly dry toast them on the pan until lightly brown and aromatic before cooking the rest of the dish and just set them aside for later.
Whole Szechuan peppercorns: If using whole peppercorns, lightly toast these then remove from the pan before adding the onions and peppers.
You can remove some oil from the same pan and leave 1 tbsp for sautéing.
In the same frying pan over high heat, add in the onions. Sauté until tender over high heat, around 1 minute.
Add in the bell pepper and cook until tender, around 2 minutes.
Turn up the heat. Add in 1 tbsp Shaoxing wine or other rice wine then leave for 30 seconds to 1 minute until it has evaporated.
Add in the szechuan pepper powder then mix well. If using whole peppercorns, I recommend to lightly toast the whole peppercorns then adding it back into the pan when the onions and bell peppers are tender.
Add in the scallions and dried chili (if using) the mix together.
Afterwards, give the sauce good mix again to prevent the starch from sticking to the bottom. Over medium heat, pour in the sauce to the pan. Immediately stir. The sauce will slowly thicken due to the starch.
When the sauce has slightly thickened, add in the crispy tofu pieces and immediately mix to coat.
By this time the sauce will have thickened into a glaze.
Turn off the heat then add in the peanuts.