So if you're looking for a sandwich filling that's anything but ordinary, beets are, yet again, the place to turn. Roasted beets are the preparation that is going to elevate your sandwich game.
Toss scallions, herbs, beets, olives, capers, and oil in a medium bowl to combine. Spread cut sides of focaccia with garlic mayo. Build sandwiches with focaccia, eggplant, feta, and beet salad.