Heat a griddle pan to hot; griddle or lightly toast the sourdough and put to one side.
Toss the halloumi with the oil and turn to coat. Add the slices to the hot griddle pan (you will need to do this in batches) leave for about a minute until griddle lines appear on the underside then turn and cook for about the same time until golden. Remove and continue to cook all the halloumi.
Top the griddled or toasted sourdough with the halloumi, drizzle over the honey and top with thyme leaves. Slice in half and transfer to a serving plate.