Cut up the tempeh and veggies before you start, because this will cook quickly and need your full attention.
Heat a wok or large frying pan to medium-high heat, then add 1-2 tsp sesame oil and tempeh. Turn occasionally, until lightly browned on all sides, about 10 minutes.
Remove the tempeh from the pan onto a plate for now, return the pan to the heat, turning up to high. Add the carrots, another teaspoon of oil, and a pinch of salt.
Keep them moving around the pan constantly so that they don’t burn. As the carrot starts to soften, add the zucchini. Then a minute or two after, the green beans. After another minute, the bell pepper, then the celery.
When they’ve softened on the outside, add a tablespoon or so of water, and keep stirring. This should sizzle and steam, which is what finishes the vegetables cooking.
Put the tempeh back in the pan, and drizzle everything with the tamari, stirring to combine and seal with heat.
Turn off the heat, and serve immediately: over cooked brown rice, quinoa, or noodles.