Spicy Orange Tofu Lo Mein

Name: Spicy Orange Tofu Lo Mein
Ingredients: 14 ounces firm tofu, cut into bite-size pieces; 3/4 cup orange juice concentrate, thawed, divided; 3 tablespoons cornstarch; 1 tablespoon fresh ginger, grated; 1 tablespoon garlic chili sauce (I love Sriracha); 8 ounces whole wheat spaghetti; 3/4 cup vegetable stock (you can use chicken stock); 2 teaspoons sesame oil, divided; 1/2 sweet red pepper, diced; 1/2 pound snow peas, cleaned; 4 ounces shiitake mushrooms; 3 mediums carrots, sliced; 2 stalks bok choy, chopped (keep the leaves separate from the stems); 1/2 small a yellow onion, sliced; 1 bunch green onions, sliced