Place the sliced cucumbers in a colander, sprinkle with ½ teaspoon of salt, and leave to drain.
In a large bowl, combine the tomatoes with about ½ teaspoon of salt.
Smash and peel the garlic cloves and combine with the remaining two tablespoons of olive oil in a small bowl; leave to rest.
Pour off excess liquid from the tomatoes. Add the drained cucumbers, red onion, fresh herbs and two tablespoons of vinegar, and mix well to combine. Remove and discard the garlic cloves from the olive oil and add the oil to the tomatoes.
Add half the croutons to the salad and toss so they absorb the liquid. Taste and adjust the salt, pepper, and vinegar to your liking.
Slice the halloumi about ¼-inch thick, then cut into bite-size pieces. Heat the remaining one tablespoon of oil in a non-stick frying pan over medium-high.
Cook the halloumi on both sides until golden-brown and crusty, approximately 1 minute per side. Add the halloumi to the salad and the remaining croutons, mix gently and serve immediately.
Tip: Halloumi is a type of Mediterranean cheese available in blocks at cheese shops and in the dairy section of many supermarkets.