One 18 - ounce tube polenta 1 1/2 tablespoons olive oil 1 tablespoon
reduced - sodium soy sauce 1 pound seitan, cut into bite - sized pieces or strips 4 large or 6 medium stalks bok choy with leaves, sliced crosswise 5 to 6 ounces fresh baby spinach 4 scallions, green and
white parts, sliced 1 tablespoon
balsamic vinegar, or more to taste 1/4 cup sliced oil - cured sun - dried tomatoes, optional Salt and ground pepper to taste