In a small bowl, whisk together the ginger, garlic, jalapeno, vinegar, 4 tablespoons of water and soy sauce. Set aside.
In a large wok over medium-high heat, heat the oil. Add the mustard seeds to the pan and cook until they start to pop, about 30 seconds. Pour in the ginger-garlic mixture and heat through, about a minute. Stir in the tomatoes and cook over medium heat until the tomatoes are softened, 5-6 minutes.
Add the corn, kohlrabi, tofu, ½ cup of water, salt and black pepper to the tomatoes. Bring to a simmer. Cover and cook on low heat for 10-12 minutes.
Stir in the garam masala and cook, uncovered, for another 2-3 minutes. Season to taste with salt and black pepper.
Serve over rice, quinoa, barley or your favorite grain.