Drain and press your block of tofu for at least 20 minutes. If you don’t own a tofu press, wrap the tofu in a kitchen towel and place a large pot or pan on top of the tofu as a press. After the tofu is pressed cut into cubes.
Place your medium sauté pan over medium heat the sesame oil or other neutral oil in the pan. Add the tofu in a mixing bowl and coat the tofu slices lightly in cornstarch. Once your pan and oil are heated, add the tofu and cook until golden brown on both sides, a few minutes on both sides. Remove the tofu and set aside.
In the same pan, stir in the sesame oil, onion, garlic, ginger, red curry paste, and Sriracha. Cook for a few minutes, stirring regularly until fragrant.
Once fragrant, add the coconut milk, then stir in the brown sugar, soy sauce, and lemon juice.
Let the curry simmer for a few minutes for a deeper flavor. Then add back your cooked tofu. Let this simmer for 5 minutes.
You can serve this tofu as is or you can serve it over rice with lime wedges, cilantro or Thai basil, green onions, and sesame seeds.
Store leftovers in an airtight container for 3 to 4 days.