Begin by baking your tofu. If you choose to purchased pre-baked tofu, then you can skip ahead. If you have time, press your tofu in a clean cloth for 30 minutes to get the liquid out. If you don't have time, it will still work, it just might not be as crispy.Preheat the oven to 400 degrees. Slice tofu into small cubes. Put cubed tofu into a medium sized mixing bowl. Toss tofu with 2 tbsp of soy sauce, 1 tbsp Mirin, minced garlic , 1 inch minced ginger, and gently stir until evenly coated.Place tofu onto a parchment lined baking sheet and bake for 20 minutes. Toss tofu and bake for another 20 minutes, until edges are golden.Set aside. While tofu is baking, add coconut milk, vegetable broth, lemon grass, and the rest of your ginger to a pot. Bring to a simmer and cook for 5 minutes.
Add mushrooms and onions and cook for another 5 minutes, until the onions are soft.
Next add lime juice, coconut sugar, the rest of the soy sauce, crushed red chili peppers and mirin to the pot and cook for another 10-15 minutes, stirring occasionally.
Finally, add the tomatoes and tofu to the pot and stir to combine. Cook for 2-3 minutes and serve. Optional to top with cilantro and/or green onions.