1. For the stock: In a large pot, place the water, mushrooms, seaweed, scallions/spring onions and onions. Bring to a boil over high heat, then reduce heat to maintain a simmer and cook, covered, for 45 minutes. Strain the stock, discarding the solids/boiled items, and set aside.
2. For the stew: In a heavy thick-bottomed medium pot, drizzle in the vegetable oil and warm over low heat. Add the onion and the gochugaru.
3. Sauté over medium-low heat, until onions are just soft, taking care not to brown them. Add the ginger and garlic, give it a quick mix, then pour in the reserved stock.
4. Bring to a simmer over medium-high heat, then stir in the courgette/zucchini, spinach, mushrooms, and napa or Korean cabbage.
5. Bring to a boil, then lower the heat to maintain a simmer and cook until the vegetables are softened, about 5 minutes. Season with salt then add the tofu carefully as it will break apart easily. Simmer until the tofu is heated through.
6. Crack a couple of eggs in on top and give it a gentle mix to break it apart and cook.
7. Garnish the stew with chopped chives, spring onions, and red chillies. Serve immediately.