Combine 2 cups boiling water and mushrooms in a small bowl; cover and let stand for 20 minutes. Drain in a colander over a bowl, reserving 1/2 cup soaking liquid. Rinse mushrooms; drain well. Discard mushroom stems; thinly slice mushroom caps.
Combine reserved liquid, sake, garlic sauce, and cornstarch in a small bowl; stir with a whisk, and set mixture aside.
Heat 1 tablespoon canola oil in a large nonstick skillet or wok over medium-high heat. Add seitan to pan, and stir-fry 2 minutes or until lightly browned. Place seitan in a medium bowl. Heat remaining 1 tablespoon oil in pan over medium-high heat. Add garlic and ginger to pan; stir-fry for 30 seconds. Add mushrooms and beans; cover and cook 3 minutes. Add bean sauce mixture to pan; cook 1 minute or until sauce slightly thickens. Add seitan to pan; cook 1 minute, stirring occasionally. Combine rice and salt; serve seitan mixture over rice. Garnish with cilantro sprigs, if desired.