Remove tofu from packaging. Place about 4 paper towels on a plate. Set tofu on top of plate and cover with more paper towels. Place a cast iron pan or something else that is heavy on top. Let sit 30 minutes.
In a medium bowl, stir together Hoisin sauce, soy sauce, sugar, ginger, garlic, and red pepper flakes.
Cut tofu into bite-sized pieces. Place in bowl with sauce and toss to coat. Let sit 30 minutes.
Heat olive oil in a medium cast iron pan over medium-high heat. Once really hot, add tofu. Once nicely seared on the bottom, flip over. Continue to cook until seared on bottom.