Bok Choy with Portobello and Tofu

1 TBS sesame oil (or canola)
1/2 package firm tofu; pressed, drained, cubed
2 stalks celery, chopped
1 1/2 cup (1/2 lb) portobello mushrooms, chopped
3 cups bok choy, chopped
1 TBS Braggs Liquid Aminos (or soy sauce)
1/2 cup low-sodium vegetable stock
1 tsp fresh ginger, grated
1 garlic clove, minced ( or 1/8 tsp garlic powder)
3 green onions, chopped
2 cups fresh spinach, chopped
2 cups cooked brown rice

1. Heat oil over medium heat. Add tofu, celery and mushrooms. Saute until tofu begins to color, about 5 minutes.
2. Place bok choy on top. Lower heat to medium-low. Cover and cook about 10 minutes.
3. Whisk together vegetable stock, ginger, garlic, and soy sauce. Pour over bok choy and stir.
4. Add onions and spinach. Cover again and cook for about 5 minutes.
5. Stir well and serve with rice.