If serving with rice - start you rice now (1 cup rice to 2 cups water is standard). If using noodles, cook to package directions later on.
Combine sauce ingredients in a small bowl and mix well to combine.
Cut tofu into bite sized cubes. Add olive oil to a medium pan and fry tofu on medium heat, tossing to brown each side.
Add 1/4 of the sauce to the tofu and coat well, frying an additional minute. Remove from heat and set the tofu aside.
Chop up your vegetables into bite sized pieces.
Either reuse the tofu pan, placing the tofu in a separate dish, or grab a new frying pan. Fry onion with a tad of water. Once translucent, add the rest of your vegetables and pan fry 5 minutes until slightly tender. Add salt and pepper and toss vegetables to incorporate.
If using udon noodles: Move your vegetables to the sides of the pan, creating an opening in the centre. Add 1/8th cup water, place your noodles on top. Pour 1/2 sauce on top, add a lid. Wait 2-3 minutes, flip the noodles, add more water if necessary. Once noodles pull apart from each other, they are done. Add remaining sauce and tofu to the pan, stir everything together and serve.
If using another type of noodle such as rice noodles or buckwheat soba noodles: Cook to the package directions, then add to the pan after vegetables are done, along with the sauce, toss to coat, add tofu and mix everything together.
Top with sesame seeds and cilantro if you wish and enjoy!