Optional: 2 jalapeños, or 1 habañero, or one of each
1 teaspoon Seasonello (with rosemary, garlic, sage, and pepper) or your favorite seasoned salt
3 tablespoons vinegar (I use rice vinegar, but cider vinegar, white balsamic, or plain old white vinegar will work)
1 teaspoon sugar
1/4 teaspoon smoked paprika
1/4 cup or more water
1/2 teaspoon Worcestershire sauce
Roughly chop the onions, garlic, and tomatillos. Heat olive oil in a large saucepan and add onions, garlic, and peppers, sautéing until soft. Add tomatillos and seasoned salt, stirring to mix. Add vinegar, sugar, paprika, and 1/4 cup water, bring to a boil, then immediately lower heat and simmer until the tomatillos are soft, about 15 minutes.
Let the sauce cool, and add Worcestershire. Puree in a blender in batches, adding water if you want to make the sauce thinner.
Notes:
Roast the peppers first to add a smokier flavor.
The first time I made this, I didn't have any peppers, so I added a few dashes of Trader Joe's habañero hot sauce. Yum.
If you're planning on serving the sauce to vegetarians, make sure to use a vegetarian Worcestershire sauce.