Combine lemon, 2 tablespoons extra virgin olive oil and sliced chillies, if using, in a large bowl.
Heat a little more olive oil in a frying pan on a medium high heat. Slice halloumi into slices about 5mm (1/4in) thick and pan fry on both sides until deeply golden, about 2 minutes each side.
Toss leaves in the dressing and divide between two plates. Top with the hot halloumi and serve ASAP