Cut tempeh lengthwise into 1/4" slices. Then, cut each slice in thirds. Set aside.
Heat a large skillet, wok, or frying pan over high heat and add avocado oil.
Once hot, add broccoli florets to skillet, cooking for ~5 minutes. Then, add bell peppers, zucchini, and tempeh slices. Continue to cook for ~10 minutes, mixing around well.
While veggies cook, mix miso-peanut sauce ingredients together in a small bowl. Adjust to taste, mix until smooth, and set aside.
Once veggie-tempeh mix is well cooked and slightly browned, remove from heat. Add cooked brown rice, noodles, or quinoa to the skillet and pour over miso-peanut sauce. Mix together well, until ingredients are coated in the sauce.
Serve and enjoy hot. Option to top with a sprinkle of red chilli flakes or hot sauce for a bit of spice!