Squeeze as much water out of the spinach and discard the water (or water your plants!). Place the spinach and cabbage in a large bowl. Sprinkle with salt and mix well. Let sit for 10 minutes. In large handfuls (or a cheesecloth), squeeze the water out of the cabbage/spinach and discard the water.
Add in the ground pork, ginger, garlic, soy sauce, wine, sesame oil and cornstarch. Mix well.
OPTIONAL: Heat up a small frying pan over medium heat, add in a touch of cooking oil. Cook a spoonful of the dumpling filling and taste. Adjust seasonings to the dumpling filling if you wish.
In a small bowl, mix together the water and cornstarch for the slurry.
Take one wonton wrapper, place 1 scant teaspoon of the dumpling mixture in the middle. Paint the outer edge of the wonton wrapper with the slurry. Fold wrapper over like in a triangle shape and seal tightly all around. Make sure there are no air pockets or holes in the wonton. Fold the two triangle points together and seal to make the wonton shape. Place folded wonton on a clean, dry plate and cover with plastic wrap or barely damp towel to avoid drying out.
When wonton are all folded, you can store or freeze.
For the broth: Set aside 2 cups of the broth. Bring the remaining broth and ginger to a simmer in a large stock pot and turn the heat to medium-high. Add in a batch of wonton. When the broth returns to a simmer again, pour in 1 cup of the reserved broth. Again, let the broth return to a simmer and then pour in the last 1 cup of reserved broth. Once the broth comes back to a simmer, the wonton should be done. Discard the ginger slices. Serve wonton and broth with few cilantro leaves if desired!