114-oz. block extra-firm tofu, drained
3Tbsp. vegetable oil, divided
12oz. mixed mushrooms (such as maitake, shiitake, and/or oyster), stems trimmed, torn into 2″ pieces
3celery stalks, thinly sliced on a diagonal
12″ piece ginger, peeled, thinly sliced
½–1 serrano chile, thinly sliced
3 Tbsp. low-sodium soy sauce
1 tsp. toasted sesame oil
1 lime, halved
½ cup coarsely chopped cilantro
Cooked short-grain rice (for serving)
Cut block of tofu into thirds crosswise, then cut each piece crosswise again into 3 pieces (you should have 9 square-ish pieces). Pat dry with paper towels.
Heat 2 Tbsp. vegetable oil in a large skillet, preferably nonstick, over medium-high. When oil is shimmering and easily slides across surface of pan, cook tofu, undisturbed, until golden brown underneath, about 4 minutes. Turn and continue to cook until browned on second side, about 4 minutes. Transfer tofu to a plate, leaving oil in pan
Pour remaining 1 Tbsp. vegetable oil into skillet and heat over medium-high until shimmering. Add mushrooms to pan and cook, undisturbed, until crisp around the edges and browned underneath, about 4 minutes. Give mushrooms a toss and continue to cook, tossing often, until browned in most spots, about 4 minutes longer. Add tofu, celery, ginger, chile, soy sauce, and sesame oil to pan. Season lightly with salt and cook, tossing often, until celery is crisp-tender, about 3 minutes. Remove from heat and squeeze in lime juice. Scatter cilantro over and toss once more.
Divide rice among bowls. Top with tofu and mushroom stir-fry.