This way of preparing Spinach has the best flavor because it helps remove some of the acids found in Spinach and brings out its sweetness. Make sure the water is at a rapid boil before adding Spinach. Taken from page 417 of the 2nd Edition of the World's Healthiest Foods book.
Fill a 3 quart pot three-quarter full with water and
bring to a boil.
While water is coming to a boil, press or chop garlic and let it sit for at least 5 minutes.
Wash Spinach as directed in The Best Way to Prepare
Spinach.
When water is at full boil, place Spinach into the pot, being extremely careful to avoid burning yourself. Do not cover. Cooking uncovered helps the acids escape into the air. Cook Spinach for 1 minute; begin timing when water starts boiling again.
After 1 minute, drain the Spinach in a colander in the sink. Press out excess liquid with fork to prevent diluting the flavor of your dressing. You want the Spinach to be tender, brightly colored, and not mushy when it's done.
Transfer to a bowl and toss Spinach with the remaining ingredients while it is still hot. (Mediterranean Dressing does not need to be made separately.) Research shows that fat-soluble vitamins and carotenoids found in foods, such as Spinach, may be better absorbed when consumed with fat-containing foods like extra virgin olive oil. Dressing helps tenderize Spinach. After 5-10 minutes it will become more tender.
Important: For best flavor, use a knife and fork to cut the cooked Spinach crosswise several times until it is in very small pieces. The more finely you
cut Spinach the more exposed surface area you create. This can allow more flavors of the dressing to pass into the Spinach and speed up desirable changes in texture including tenderness.