Prepare the sauce by combining all the sauce ingredients. Mix well. Set aside.
Heat oil in a pot.
Once the oil gets hot (around 350F), deep fry the cubed tofu until it turns light brown. Remove from the pot and place in a plate with paper towel. Set aside
Scoop 3 tablespoons cooking oil from the pot where the tofu was fried. Heat it in a separate clean pot.
Saute onion and bell peppers.
Add the fried tofu. Cook for 2 minutes.
Pour half of the sauce mixture into the pot. Stir and continue to cook for 2 minutes.
Heat a sizzling plate on the stovetop. Melt butter into the plate. Transfer cooked tofu on the metal plate and pour the remaining sauce. Toss and cook for 1 minute.
Serve. Share and enjoy!