Adjust oven rack to the middle and heat the broiler on high. Cut peppers lengthwise and set cut-side down on a baking sheet (line with foil for easier cleanup). Broil for 10 to 12 minutes, checking in at the nine-minute mark. The peppers should be charred and blistered. Carefully transfer to a bowl; cover to trap steam. Cool until comfortable to handle. Peel.

In a chopper or small food processor, mince the garlic. Add the jalapeños, mayonnaise, za’atar, salt and pepper. Pulse until pureed but still slightly chunky. Transfer to an airtight container.

Refrigerate for up to five days. If freezing, omit the mayonnaise and wrap the container well in plastic wrap. Add mayonnaise after thawing.