They are actually not related to tomatoes. Sometimes referred to as a husk tomato, they are cousins of the lowly ground cherry. Tomatillos are a bit tart and kind of lemony, except not. Boy, I'm destined to become a food writer aren't I? They are great fresh in salsas, in a stew, or made into ketchup. What!? Yes, it sounds weird but it is terribly delicious. I recently stumbled upon a recipe for Tomatillo Green Chile Ketchup, from Marissa McClellan. She writes a great canning blog called Food In Jars, and developed this recipe for Saveur magazine. I knew I had to try it. I doubled the batch (that's how optimistic I was) and it was really, really good! So good I have since made another double batch of it.
Tomatillo Green Chile Ketchup
Put all ingredients in a large pot and simmer til softened. Use an immersion blender to puree til smooth (see...that's how you can skip all the chopping!). Simmer til thickened to your liking. Keep in mind it will thicken a bit more as it cools also. If you'd like, it can be processed in a water bath for 15 minutes, or just store in the refrigerator. Makes 3 cups.