Cook brown rice according to package instructions.
Dice mushrooms, slice orange bell pepper and cut tomatoes in half.
Heat cooking oil over medium heat, add mushrooms, bell pepper and tomatoes. Saute for 8-10 minutes. Then add black beans and cook for 2-3 more minutes.
To make the teriyaki sauce, add all sauce ingredients to a small pot and whisk together. Warm sauce over low / medium heat until you see the first bubbles, then turn the heat off, stir and let sit. Be careful not to over cook the sauce, but if you do simply whisk in a tablespoon or two of water.
Thinly slice spinach and cabbage.
Build bowls with rice, spinach and cabbage, cooked veggies, top with sauce and sesame seeds. Enjoy!