To cook the eggplant, add a thin layer of oil to cover a large non-stick skillet bottom (I used 12").
Arrange the eggplant in the pan in one single layer, stuffed side facing up. I cook mine in 2 separate batches. Pan-fry over medium-low heat until the bottom turns slightly brownish. Carefully flip the eggplant and pan-fry this side until a thin crust forms, about 3-5 minutes.
Flip the eggplant again so the stuffed side faces up. Season with 1 tablespoon of each (I half the sauce since I cook mine in 2 batches): light soy sauce, vegan oyster sauce, and doubanjiang. Then, slowly add in 1½ cups of water. Bring it to a boil and cover the pan with a lid and braise for 2-3 minutes over medium heat until the flavors meld and the eggplant is fully cooked through.
While waiting, mix 2 teaspoons of cornstarch with 1 tablespoon of water to make a slurry.
Uncover and swirl in the cornstarch slurry to thicken the sauce. Transfer a plate. Repeat the same cooking step with the remaining eggplant if cooking in 2 batches. Garnish with chopped red jalapeños, scallions, and toasted sesame seeds. Serve warm with rice.