Serves 4

1 package of extra-firm tofu
2 tablespoons peanut or vegetable oil
2 scallions, white and green parts separated and thinly sliced
8 cremini mushrooms, stems discarded and caps quartered
1/2 teaspoon white sesame seeds

Sauce:

1 cup dark brown ale (preferably a nutty one with a good amount of sweetness)
1/2 cup no-chicken stock
1 tablespoon soy sauce
1 tablespoon Chinese rice wine or dry sherry
2 to 3 teaspoons Sriracha
1/2 tablespoon hoisin sauce
2 teaspoons sesame oil
1 tablespoon sugar sugar
1/4 teaspoon salt