First, prepare the tofu. If you haven't already, press the tofu for at least 15-20 minutes to remove excess water.
Slice it into ½-inch thick pieces.
In a shallow dish or bowl, whisk together all the marinade : soy sauce, vegetable oil, vinegar, grated ginger, scallions, sesame oil, minced garlic, black pepper, and hot pepper flakes.
Add the tofu slices to the marinade, ensuring each piece is coated.
Let it marinate for at least 15 minutes, but 30 minutes or longer will result in a deeper flavor.
Choose your cooking method
For Soft, Simmered Tofu: Pour the tofu and all the marinade into a frying pan.
Cover and simmer over medium-low heat for 5-7 minutes, until heated through.
For Crispy, Pan-Fried Tofu: Heat 1 tablespoon (15 ml / 0.5 fl oz) of oil in a frying pan over medium-high heat.
Remove the tofu slices from the marinade, letting excess liquid drip off (reserve the marinade).
Pat the slices dry and lightly coat them in cornstarch.
Place the tofu in the hot pan in a single layer and cook for 2-4 minutes per side, until golden brown and crispy.
If using, add the chopped cabbage or spinach to the pan. For the crispy method, you can add the reserved marinade back to the pan with the vegetables.
Simmer and stir for another 3-5 minutes, until the vegetables are wilted and the sauce has slightly thickened.
Serve immediately over a bed of warm cooked rice with a side of your favorite vegetables.
Marinate for at least 30 minutes for good flavor, or up to 24 hours in the refrigerator for an even more savory result.
Don't discard the leftover marinade!
Simmer it in the pan for a minute or two to thicken it into a delicious sauce to pour over your dish.