Creating Korean Soft Tofu Stew is simple if you follow these steps:

1. Heat the Oil: In a large pot, heat the vegetable oil over medium heat.
2. Sauté the Aromatics: Add the diced onions and sauté until translucent. Then, add the minced garlic and sliced green chilies, cooking until fragrant.
3. Add the Gochugaru: Stir in the gochugaru, mixing well to coat the onions and garlic in the spice.
4. Pour in the Broth: Add the vegetable or chicken broth to the pot and bring it to a boil.
5. Add Vegetables: Once boiling, add the sliced mushrooms and diced zucchini. Let it cook for about 5 minutes or until the vegetables are tender.
6. Incorporate the Tofu: Gently add the cubed soft tofu to the pot. Be careful not to break the tofu too much.
7. Season the Stew: Stir in the soy sauce, sesame oil, and salt to taste. Let the stew simmer for another 5 minutes.
8. Add Greens: Add the spinach or bok choy and cook for an additional 2-3 minutes until wilted.
9. Optional Egg: If desired, crack an egg into the stew just before serving. Let it cook for a minute or two until the egg is set.
10. Garnish and Serve: Remove from heat, garnish with chopped green onions, and serve hot.

These steps will guide you in creating this amazing Korean Soft Tofu Stew effortlessly.