Heat a large skillet to medium heat
Add 1 tsp oil
Add the garlic, scallions, and chili pepper, and gently stir in the oil for 1 minute.
Add 1 tbsp of Szechwan sauce (or other sauce) and 1 tbsp water to skillet and gently stir for 15 seconds.
Add the cooked eggplant into the sauce and gently coat all pieces with the sauce, gently mixing for about 5 minutes.
Taste and add 1 tsp to 1 tbsp of sauce if needed, then let cook for another minute.
Garnish with chopped scallions (optional)
Remove from heat and serve hot.