Ginger Soba Noodles

Name: Ginger Soba Noodles
Ingredients: 12 oz/340 g dried soba noodles; 1 tablespoon freshly grated fresh ginger; 1 teaspoon toasted sesame oil; zest and juice of 1/2 a lemon; 1/2 cup/2.5 oz/70 g chopped white onion; 1 teaspoon mirin (optional); 2 teaspoons brown sugar or honey; 1/2 teaspoon salt, plus more to taste; 3 tablespoons brown rice vinegar; 1 celery stalk, strings removed, then chopped; 1/3 cup/80 sunflower oil or untoasted sesame oil; 3 tablespoons of chopped tarragon, plus more to taste; a few big handfuls of cubed tofu, pan-fried or baked until golden; 1/3 cup + toasted squash seeds, pumpkin seeds, walnuts, or sesame seeds