Step 1

In a small bowl, mash avocado well. Stir in olives, lemon juice, and za'atar. Season with salt.

Step 2

Using a serrated knife, slice ka'ak in half and toast.

Step 3

Meanwhile, set a 10-inch nonstick skillet over medium heat, add halloumi, and cook, turning once, until well browned on each side, about 2 minutes per side.

Step 4

Spread avocado mixture on ka'ak halves. Top each with 2 slices warm halloumi. Sprinkle with za'atar and serve open-faced.