In a wok or large pan over medium heat, add the vegetable oil and let it get hot. Add the ginger and garlic and saute just until fragrant, then add the cabbage and carrot. Toss to coat in the oil.

Add about 1/4 cup of water to the pan and cover. Steam the vegetables until tender, soft, and wilted, about 20 to 30 minutes. Check every few minutes to make sure there is still water in the bottom and stir; add a splash more water if the pan goes dry.

While the veggies steam, stir together the soy sauce, peanut butter, sesame oil, rice wine, dark soy sauce, salt, and pepper in a small bowl until smooth.

Add the sauce to the pan once the vegetables are done. Cook out any excess water and stir to coat evenly. Pour the mixture into a mesh colander set over a bowl to drain off the liquid.

Place the filling in the fridge for at least an hour, or until cool to the touch. Discard the roughly 1/2 cup of liquid that drains off. Stir in the pulled pork.

Combine equal parts flour and water to form a thin paste; you only need a little. This is the glue that keeps the egg rolls closed while they fry.

Set up a rolling station. Place 1 to 2 tablespoons of filling on a wrapper, fold in the sides, roll up tightly, and seal the final flap with the flour paste. Repeat until the filling is gone.

Add enough vegetable oil to come about 2 inches up the side of a pan and heat over medium until it reaches 350F.

Lower the egg rolls into the hot oil one at a time. They fry fast, so keep an eye on them and turn halfway through, about 2 to 3 minutes total, until golden brown on all sides.

Transfer the fried egg rolls to a cooling rack set over a sheet pan to let the excess oil drip off. Serve hot with sweet and sour sauce or hot mustard.