Preheat oven to 425°F. In a large bowl, add the quartered Tomatillos (stems removed), unpeeled Garlic cloves and the quartered Onion. Slice the Jalapeño Pepper into four or six lengthwise strips, and remove the seeds and membrane. Add the strips into the bowl. Drizzle with olive oil to just coat. Sprinkle with salt and pepper.Line baking sheets with aluminum foil. Spread the vegetables out on baking sheets: if they are piled together, they will steam rather than roast. Roast at 425°F until just charred, about 20 minutes. Squeeze the roasted Garlic out of its skins. Peel the Peppers. Put the roasted Garlic and all of the roasted vegetables into the food processor. Add the lime juice and apple cider vinegar. Process until smooth. Pour into a bowl. Add the Cilantro and Scallions, and salt and pepper to taste. Serve as a dipping sauce with chips. It’s also good drizzled over the contents of tacos, quesadillas and fajitas.