Let's get started. Put a skillet, that is big enough to handle all of the zucchini laying flat, on at medium high and eyeball about 2 tablespoons of olive oil. If you have to do it in batches it's ok. It's going to come together pretty quick so get the vegetables all ready to go. Slice the zucchini in about 3/8" slices. Chop up the garlic, cut the onion into strips and quarter the lemon.
Put the zucchini and the onion in the pan and lightly salt and pepper.
About two minutes or when they are starting to get brown turn them over and salt and pepper the cooked side. Another couple of minutes and push everything off to the sides. Put the garlic in the bare spot. Squeeze the lemon onto the garlic and eyeball about a tablespoon of good extra virgin olive oil onto the garlic let the garlic cook a little. Don't let it get brown!
Gently mix everything together and drizzle a little balsamic vinegar on it then mix again. Remove it all to a dish lined with paper towels to let the olive oil drain off. We really like this veggie dish and I'll bet that you will too.
Bon Appetit! And don't forget, it's just as good at room temperature if you have more to do.