Combine soy sauce, rice vinegar and brown sugar in a bowl to make the sauce. Stir to combine and set aside.
Press tofu to remove the excess water
Then cut to tofu into cubes.
Place the cut tofu in the sauce and marinate for 20 minutes.
In a large pan, heat the olive oil on medium heat.
Carefully remove the tofu from the sauce and add to the pan. Fry until crispy on each side.
Remove the tofu and sauce from the pan and set aside.
In a large skillet, heat sesame oil over medium heat.
Cook onions and carrots until they begin to soften.
Add bell peppers, spinach, ginger and garlic.
Stir fry for 2-3 minutes until peppers begin to soften.
Add peanuts and tofu and combine all ingredients together.
Simmer until the sauce has thickened slightly.
Remove from heat
Serve over rice if desired.