Step 1: Prepare the Halloumi
Remove the halloumi from its brine packaging and pat it completely dry with paper towels. This is crucial—any excess moisture will prevent proper browning and create steam instead of that desirable crispy crust. Once dry, cut the halloumi block into slices about ½-inch thick. You should get 6-8 slices depending on the size of your block. Set aside on a clean plate.

Step 2: Prep Your Vegetables and Bread
While you’re preparing the halloumi, slice your tomatoes, cucumber, and red onion into thin, even pieces. Wash and dry your lettuce or arugula leaves. If you’re using any optional add-ins like roasted red peppers or avocado, prepare those as well. If you prefer toasted bread, toast your slices now and set them aside. Having everything ready means quick assembly once your halloumi is cooked.

Step 3: Heat Your Pan
Place a non-stick skillet or grill pan over medium-high heat. Let it heat for 2-3 minutes until hot but not smoking. You want a good sear on the halloumi, but not so hot that it burns before developing that golden crust. Test the temperature by dropping a tiny bit of water on the pan—it should sizzle immediately.

Step 4: Cook the Halloumi
Add 1 tablespoon of olive oil to your hot pan and swirl to coat the surface. Carefully lay your halloumi slices in the pan, making sure they’re not touching (work in batches if necessary). Let them cook undisturbed for 2-3 minutes. You’ll see the edges start to turn golden. Resist the urge to move them around—patience gives you that beautiful crust! When the bottom is deep golden brown with some darker caramelized spots, flip each slice using a spatula. Add the remaining tablespoon of olive oil if the pan looks dry. Cook the second side for another 2-3 minutes until equally golden and crispy.

Step 5: Finish the Halloumi
Once both sides are beautifully browned, immediately squeeze fresh lemon juice over the hot halloumi slices and add a few grinds of black pepper. The lemon juice will sizzle and create a lovely, bright finish. Remove from heat promptly—halloumi can become rubbery if overcooked.

Step 6: Assemble Your Sandwiches
Lay out your bread or sliced rolls. Spread your chosen sauce (pesto, hummus, or tzatziki) generously on both slices of each sandwich. This creates a flavorful moisture barrier and helps everything stay together. On the bottom slice, layer your arugula or lettuce first, then add the warm grilled halloumi slices (about 3-4 per sandwich), followed by tomato slices, cucumber, and red onion. Add any optional ingredients you’re using. Top with the second slice of bread and press down gently to help everything adhere.

Step 7: Slice and Serve
Cut each sandwich in half diagonally for easier eating and that appealing presentation. Serve immediately while the halloumi is still warm and at its best texture. The contrast between the hot, crispy cheese and the cool, fresh vegetables is what makes this sandwich so special!