Cut bread into four pieces, then split each piece in half. Brush insides of bread with 4 teaspoons olive oil.
When pan is hot, add bread oil-side down. Cook until bread is warm and golden. Set aside. (You may need to do this in batches, depending on pan size.)
Wipe out pan, then add 1 tablespoon olive oil. Place halloumi slices in pan, then cook over medium heat until light golden brown. Flip, then repeat on other side.
Spread both sides of bread with pesto mayo, then top with baby greens. Add halloumi, then top with sliced tomato.
Serve sandwiches immediately, while warm. Enjoy!
Prepare Pesto Mayo:
While bread and halloumi cook, place mayonnaise in a small bowl. Mix until smooth, then stir in pesto.
Notes
I used a 1-pound (454 grams) loaf of ciabatta to make these sandwiches. Other types of bread, such a french bread, will also work in a pinch. Avoid anything too chewy or dense.Watch the halloumi carefully, to avoid over cooking. It should be a light golden color on both sides when done.Check out info before recipe card for lots of tips and variations.