Heat your pan hot, hot hot! Add the red onion and cook, stirring frequently, add a splash of water after a few minutes to deglaze your pan, takes about 4-5 minutes. Add the garlic and continue cooking until it's all very soft, about 7 minutes in total. Deglaze the pan a second time if needed. Set aside in a bowl.
Place the zucchini in your hot pan and let it brown a little by sitting in the hot pan without too much stirring.
Add the tomatoes and stir. Add the onions and garlic and stir everything together until the tomatoes collapse making a little sauce.
Stir in the fresh or dried basil and serve!
This recipe can also be used as a sauce for pasta dishes - lovely and fresh - full of the flavours of Summer.