Wrap tofu block in several layers of heavy-duty paper towels. Press with a heavy object for about 30 minutes to remove excess water. Remove paper towels, pat tofu dry, and cut lengthwise into 8 slices.
Combine hoisin sauce and next 5 ingredients; set aside.
Heat oil in a large nonstick skillet over medium-high heat. Add tofu slices; cook 5 minutes on each side or until lightly browned. Remove from pan and keep warm.
Add hoisin sauce mixture to pan. Cook over medium heat 4 minutes or until thick, stirring constantly with a whisk. Return tofu to pan; cook 30 seconds. Serve with brown rice.