Step 1: Press the tofu. Wrap the block of tofu in several layers of paper towels or a clean kitchen towel. Place it on a plate and top with a heavy object (like a cast iron skillet or a few cans) for at least 30 minutes, or up to 2 hours, to remove excess water. Cut the pressed tofu into 1-inch cubes.
Step 2: In a medium bowl, gently toss the tofu cubes with cornstarch until evenly coated. This step is crucial for crispy tofu.
Step 3: Heat olive oil in a large non-stick skillet or wok over medium-high heat. Once hot, add the cornstarch-coated tofu in a single layer. Cook for 5-7 minutes, flipping occasionally, until all sides are golden brown and crispy. Remove the crispy tofu from the skillet and set aside.
Step 4: In the same skillet, reduce heat to medium. Add the minced garlic and grated ginger (if using). Sauté for 30 seconds to 1 minute until fragrant, being careful not to burn the garlic.
Step 5: In a small bowl, whisk together the soy sauce, rice vinegar, sriracha (or chili garlic sauce), maple syrup (or brown sugar), and water/vegetable broth to create the sauce.
Step 6: Pour the sauce into the skillet with the garlic and ginger. Bring to a gentle simmer, stirring constantly, until the sauce thickens slightly, about 1-2 minutes.
Step 7: Return the crispy tofu to the skillet and toss gently to coat evenly with the sauce. Cook for another 1-2 minutes, allowing the tofu to absorb the flavors and the sauce to further thicken and cling to the tofu.
Step 8: Remove from heat. Garnish with sliced green onions and sesame seeds. Serve immediately over rice, noodles, or with your favorite steamed vegetables.