Start by cutting the pressed tofu into bite-sized cubes. Toss the tofu cubes with cornstarch until well-coated.
Heat 1 tablespoon of vegetable oil in a large non-stick skillet or wok over medium-high heat. Add the tofu cubes and cook until golden and crispy on all sides, about 8-10 minutes. Remove the tofu from the skillet and set aside.
In the same skillet, add the remaining tablespoon of vegetable oil. Sauté the minced garlic and grated ginger for about 1 minute, until fragrant.
Add the sliced red bell pepper, broccoli florets, and snap peas to the skillet. Stir-fry for 4-5 minutes or until the vegetables are tender but still crisp.
Stir in the cooked tofu, lemon zest, lemon juice, soy sauce, and sesame oil. Mix everything together until well combined and heated through, approximately 2 minutes. Season with salt and pepper to taste.
Remove from heat and garnish with chopped green onions and sesame seeds.