Wash the spinach thoroughly and trim any tough stems or bad spots on the leaves. Drain the spinach and pat dry with a paper towel. Coarsely chop the spinach.
Assemble all of your prepared ingredients beforehand as the cooking is quick.
Place a wok or large skillet over medium-high heat. When the pan or wok gets smoking hot, add the peanut oil with the garlic and onion. Stir fry the onion and garlic for 30 seconds, the add the spinach and water chestnuts. Continue to cook an additional 3 minutes, allowing the water from the spinach to cook off.
Transfer the vegetables from the wok or pan to a bowl. Season with salt and pepper to taste. Allow the spinach to cool for 5 minutes.
To form the wontons, pull one wonton from the package an moisten the edges with water. Place a scant teaspoon of the spinach mixture in the center of the wonton. Fold the wonton over into a triangle. Now, fold the long corners together and give them a wee pinch to hold together.
Cover the completed wontons with plastic wrap to prevent the wrappers from drying out.
There are several options on how to cook prepared wontons. You can simmer them in some vegetable or chicken broth for a good soup. Add some nice veggies to make this a soup entree.
You can also steam them and serve with a soy dipping sauce.
You can also deep fry them in oil, also serving them with dipping sauce.
Prepared won-tons can be frozen by placing single-layer them on a cooking sheet. Once frozen, transfer them to a resealable bag and you can take out what you need.