Drain the eggplant and pat dry with a towel. Toss with the corn starch.
Working in 2 batches, heat 1 -2 tablespoons oil in an extra-large skillet over medium heat. Add half the eggplant spreading them out. You want to get both sides nice and golden, and the insides cooked through -so take your time here and dont rush this step. Let one side brown then turn them over using tongs. This will take about 10 minutes for each batch. ( If in a hurry sometimes I’ll use 2 pans.) Set the eggplant aside.
Add 1 more tablespoon oil to the skillet, and over medium heat, add the garlic and ginger, stirring for 2 minutes. Turn the fan on, add the dried chilis and stir one minute. Pour the Szechuan sauce into the pan and bring to a simmer for 20 seconds. Add the eggplant back into the skillet, tossing gently for about 1 minute. If it seems dry add a tablespoon of water to loosen.
Place in a serving dish and top with scallions and optional peanuts.