Cut the zucchini in half, scrape out seeds and soft parts. Spray the zucchini with olive oil, spices to taste and grill both sides. Save the seed parts to mix into the "stuffing". OR discard (I don't like the seeds) and use quinio or brown rice.
Grill chopped onions, tomatoes, carrots, peppers, cauliflower, any veggies that you like. Mix with quinio or rice and fill zucchini halves. I like to sprinkle feta cheese on top sometimes.
TBH, I haven't made these in a while. I usually just end up chopping up the zucchini to add to the other grilled veggies since I am a lazy cook. But if I want to impress my guest, I will also stuff grilled peppers and onions with the same filling.
I have also stuffed the zucchini with spaghetti squash, tomatoes, a little sauce, spices and parmesan cheese.