1 14-ounce package extra-firm water-packed tofu, rinsed
1/2 teaspoon five-spice powder, (see Shopping Tip), divided
1 tablespoon canola oil
1/2 cup water
3 tablespoons oyster-flavored or oyster sauce, (see Shopping Tip)
1/2 teaspoon cornstarch
12 ounces broccoli crowns, (see Ingredient Note), trimmed and cut into bite-size pieces (4 cups)
1 yellow bell pepper, cut into 1/2-inch dice
1 red bell pepper, cut into 1/2-inch dice
1 tablespoon minced fresh ginger
1 tablespoon minced garlic
2 tablespoons unsalted roasted peanuts
2 teaspoons hot sesame oil, (optional)