Step 1: Cook the Gyoza
1. Heat Oil: In a large skillet or frying pan, heat the vegetable oil over medium heat.
2. Fry Gyoza: Add the frozen gyoza to the pan and cook for about 2-3 minutes until the bottoms are golden brown.
3. Add Water: Carefully add about 1/4 cup of water to the pan and cover immediately. Steam the gyoza for about 5-7 minutes until they are cooked through and the water has evaporated. Remove from heat and set aside.

Step 2: Prepare the Soup
1. Combine Broth Ingredients: In a large pot, combine the chicken or vegetable broth, water, sliced green onions (white parts), mushrooms, garlic, ginger, soy sauce, and sesame oil. Bring to a simmer over medium heat.
2. Add Greens: Once the broth is simmering, add the bok choy or spinach and cook for an additional 2-3 minutes until the greens are wilted.

Step 3: Assemble the Soup
1. Add Gyoza: Gently add the cooked gyoza to the soup and let them warm through for about 1-2 minutes.
2. Season: Taste the soup and adjust seasoning with salt and pepper as needed.

Step 4: Serve
1. Garnish: Ladle the soup into bowls and garnish with optional toppings such as sesame seeds, chili oil, or additional green onions.
2. Enjoy: Serve hot and enjoy your comforting gyoza soup!