Cut Tofu into 1" cubes. Slice green onions thinly. Mince ginger and garlic and set aside. Slice mushroom. In a bowl, mix all the ingredients for the sauce until Miso dissolves. Set aside.
Heat oil in a large skillet or a wok at medium heat, add garlic, ginger, and red pepper, and stir. Add the ground pork and cook until browned. Add the mushroom and spinach and cook until wilted. Add the sauce and let it boil. Add the cubed tofu and stir gently.
When Tofu is cooked through, stir in green onions and sesame oil. Serve over rice (optional).