If using, soak the shiitake mushroom caps in hot water.
Whilst the mushrooms are soaking, mix the sauces in a small bowl and leave it by the stove.
Cut the washed eggplant into batons, about 1.5-2 inches in length. Dry with a paper towel.
Sprinkle 1 Tablespoon of cornstarch over the eggplant in a thin layer- this helps it develop a nice texture when stir-frying. Note: Use your hands to make sure they're evenly coated. Place the coated aubergines in a sieve and shake off any excess starch. Over medium heat, heat 1-2 teaspoons of oil till it is shimmering but not smoking in a large skillet of wok. Swirl the oil around.Note: You want just enough oil to coat the surface of the pan. Don't use too much or the eggplants will just absorb it oil. You will need to add more oil each time you brown a new batch of eggplants. High heat is crucial for Chinese stir-fries but if the oil ever smokes, reduce the heat. Add the eggplant pieces in a single layer- as many as we can squeeze in because we don't want to be browning eggplants forever- and leave to brown. The eggplants will darken, soften, and wrinkle a bit. In an ideal world, we would brown every side, but we have hungry people waiting to eat, so just brown 1-2 sides per baton. (See Tips for how to steam instead of browning the eggplants.)
Once browned, remove from the pan. Repeat till all the eggplants are charred. (You will need to add more oil for every batch. See post for how the eggplants look when there is not enough oil.)
Add 1 Tablespoon oil to the pan over medium high heat or high heat. Once the oil is hot and shimmering, quickly stir-fry the ginger and garlic till fragrant, 30-45 seconds.
Add the dried and fresh mushrooms to the pan, along with some sliced spring onions and red chilies. Keeping stirring for 1-2 minutes. It may feel a bit hard to stir initially but the mushrooms will release water, so it'll get easier. If the pan really feels too dry add some water or stock.
Return the eggplants to the pan.
Add the sauce mixture to the pan and stir a few times till everything is well-coated.
Pour in the vegetable stock or water, bring to the boil and cook down, till you get a rich, thick and glossy sauce. This will just take a few minutes. Note: If you added too much cornstarch or heated it for too long and the sauce is too thick, just add more water or broth. Stir till the eggplants are all well-coated in the sauce and switch off the fire. Garnish with sliced red chilies and sliced green onions.Serve with white rice, brown rice or cauliflower rice!