Toss the sliced aubergines with some salt in a large microwavable bowl with a lid, then cover tightly and microwave for 10 minutes, tossing halfway through. The aubergines should be completely cooked - if you have a powerful microwave and a tight seal you might get away with 7-8 mins, if it's less powerful and you don't have a tightly fitting lid, you will need more time.
While the aubergines are nuking, fry the garlic slices over high heat in a little oil until turning golden but not burning. Add the diced tomato, oregano, 2 tsp paprika, 2 tsp sugar (or equivalent amount of sweetener) and season with salt and pepper. Cook down, stirring often, until the tomatoes have broken down and the sauce is delicious, thick and chunky.
Put a ridged grill pan on high heat and heat until very hot. If your grill pan is non-stick, use as is, but if not, brush with some heat-resistant oil to stop the aubergines sticking.
Remove the aubergines from the microwave bowl onto a chopping board and sprinkle with salt, pepper and paprika on both sides. Add to the grill pan and cook until those lovely burnt lines get there, flipping once, about 3 minutes on each side (depending on how hot your stovetop gets). Remove to a serving platter, and arrange in a single layer with some overlap.
While your last batch of aubergines is grilling, taste and adjust the seasoning on your tomato sauce. If it's correct, add in the orange blossom water, mix thoroughly and taste again, adding a little more if needed. Orange blossom water can be extremely strong and overpowering, so use less rather than more.
Spoon the tomato reduction over the warm aubergine, top with crumbled feta and serve warm.