Prep: Preheat the oven to 425F and line a baking sheet with a silicone mat or parchment paper. Tear the tofu into bite-sized chunks for a more meat-like shape and texture, or cut into small cubes.
Tofu: Add the tofu to a medium bowl and add in the oil and tamari. Toss with a spatula until evenly coated, then sprinkle the cornstarch on top and toss again. Transfer to a baking sheet and spread out the tofu pieces so they aren’t touching. Bake on the top rack of the oven for 30 minutes, flipping the tofu halfway through.
Sauce: In the meantime, whisk the hoisin sauce, vinegar, tamari, cornstarch, and water together in a small bowl. Set aside.
Stir-Fry: Warm the oil in a large sauté pan, large skillet, or wok over medium heat, then fry the white parts of the green onion and the garlic for 1 minute. Pour the hoisin sauce mixture over the aromatics and bring to a simmer, stirring occasionally. Add the crispy tofu and sesame seeds; stir into the sauce. Finally, turn the heat off and stir in the toasted sesame oil and remaining green parts of the green onion.
Serve: Serve over rice and vegetables, or as desired. Leftovers will keep in the fridge for up to 5 days.
Gluten-Free: Use a gluten-free hoisin sauce (some contain wheat) and tamari or gluten-free soy sauce to make this recipe gluten-free