Preheat oven to 425 degrees. Trim bean sprouts. Blanch just until tender in boiling water and pat dry. In a large pan stirfry bean sprouts with soy, sesame oil, sesame seeds, garlic, ginger and spring onions. Season with salt and pepper. Thinly slice cucumber. Sprinkle with salt and cover with cold water. Allow to sit for one hour. Drain, rinse in fresh water and pat to remove excess water. In a large bowl combine vinegar, sesame oil, and sesame seeds. Add cucumber and toss to coat. To prepare: Place a layer of cooked rice in 4 heated oven-proof bowls. Arrange layers of the bean sprout mixture, cucumber mixture, Fiddlehead Salad and Spinach Salad over rice. Place in oven for 5 to 10 minutes. Sprinkle with kingui and toasted sesame seeds. Add kochujang to taste. Serve with kimchi.
In a large pot of boiling, lightly salted water, blanch spinach for about 2 minutes, until just tender. Drain well. Pat the spinach dry with a towel or squeeze dry with hands. Chop spinach into large pieces. In a large bowl combine sugar, soy and sesame oil. Add spinach add toss to coat. Sprinkle with sesame seeds. Serve warm or chilled.
In a large pot of boiling, lightly salted water, blanch fiddleheads until just tender. Drain well. In a large bowl combine sugar, soy sauce and sesame oil. Add fiddleheads and toss to coat. Sprinkle with sesame seeds. Serve warm or at room temperature.