Make the salsa. Chop the melon into 1/2" dice and place into a small mixing bowl. Cut each end from the lime and stand it on it's end. Using a sharp knife, carefully slice the skin and pith from the lime, taking care not to cut away too much flesh. Ideally, you want to remove the segments from their membranes and chop them up. Do this by holding the lime in your hand and carefully slicing along the membrane at each side of the segment so that the flesh comes away. If you don't want to do this, you can chop the whole fruit but be warned, it will be a little chewier this way and there will be a slight bitterness. But it's up to you. Add to the melon.
De-seed and finely chop the jalapeño. Depending on the heat of your chilli and how hot you like your food, add as much as you like to the salsa. My jalapeños were pretty hot so I only used half. Chop the coriander and add that too. Stir and set aside. There is no need to add any salt.
Slice the halloumi and dry fry over a medium heat until browned. Once the first side has browned, flip over and scatter the seeds over the top. Once browned all over, flip the halloumi to ensure it's well coated.
Place the rocket leaves onto a large plate or platter. Top with the seedy halloumi and spoon the salsa over the top. Serve immediately.