Using a vegetable spiralizer or a peeler, cut zucchini into noodle ribbons. You can simply slice it as well. Set aside.
Heat a tablespoon of olive oil in a large frying pan over high heat. Add the prawns and pan fry for 2 minutes, stirring a few times. Remove to a bowl.
Turn the heat to medium and add 2 more tablespoons of olive oil to the pan. Add the diced onion and peppers, and sauté for about 3 minutes, until lightly browned and softened.
Then add the salt, chilli and garlic and stir through. Pour in the tomatoes and mix well. Cook for a couple of minutes over medium heat, stirring a few times. You can add a little splash of water if the tomatoes start to dry up.
Now add back the prawns and the zucchini noodles. Stir together for a minute or two, until well heated through and combined. The zucchini should soften slightly but not too much as it will start to give out juice and will turn soggy.
Serve in bowls with some grated cheese, if you like, or some fresh chopped herbs.