Following links I found this recipe for tomatillo sauce. I decided to give it a try, but not process it as I didn't have many tomatillos and was making a very small batch.
Onion and peppers from my mother's garden. Tomatillos from mine. I used lime juice, salt and cumin. Plus a bit of olive oil and water (to rinse out the jar I blended the sauce in).
It's so good I'm hoping there will still be tomatillos at the farmer's market so that I can make a bigger batch and process it (leaving out the olive oil and extra water).
At the very least, I know what I'll be doing with the tomatillos I froze.