Mix your marinade ingredients together.
Prepare all your sauté ingredients and have them within arms reach of the stove.
Boil a large pot of water and add soba noodles. Cook as per package instructions.
Meanwhile, heat a splash of sesame oil in a large pan, or well-seasoned wok over almost medium heat. When it is hot, add the tofu, and cook until golden – a few minutes. If using fish or prawns/shrimp, poach with a touch of sesame oil and a sprinkle of water and cover until almost ready and set aside.
Once the soba noodles are done (only a few minutes), rinse with cool water and mix in a drizzle of sesame oil to keep from sticking. Allow to cool and put in fridge if you are having it as salad.
Add another (generous) splash of oil to the pan and, at moderate heat, add the onions, asparagus, and salt. Stir fry for about a minute or two, then add the garlic, cashew/sesames (reserving a few for garnish), and spinach and stir-fry for another minute, or until the spinach wilts.
Return the tofu to the pan. Stir in the marinade, if having warm. Cook for another minute or so, tossing your ingredients about in the marinade. *If you’re having your noodles as a cold salad reserve some of the marinade for just before serving as the noodles will absorb much of it.
Remove from heat and stir in the mint and basil and garnish with nuts/seeds. Taste and adjust as needed.