Prep tofu: Press tofu for 15–20 minutes. Cut into cubes.
Cook tofu: Heat oil in a non-stick skillet. Pan-fry tofu until golden on all sides. Remove and set aside.
Sauté veggies: In the same skillet, add more oil if needed. Sauté garlic and ginger for 30 seconds, then add eggplant (and bell pepper if using). Stir-fry for 6–8 minutes until soft and slightly browned.
Make sauce: In a bowl, whisk soy sauce, hoisin, vinegar, sesame oil, and cornstarch.
Combine: Return tofu to the pan. Pour in the sauce. Stir to coat everything. Simmer for 2–3 minutes until thickened.
Serve: Top with sesame seeds and scallions. Pair with rice, noodles, or One Pot Cauliflower Fried Rice.