Place all vegetables in a large glass container with a lid.
Place sugar, oil, vinegar, salt and pepper in a saucepan. Heat and stir until sugar dissolves.
Pour over vegetables, and gently stir. Refrigerate overnight. When ready to serve, stir again, then transfer to a bowl, using a slotted spoon to do so, as the marinate tends to make more juice overnight.
Note: you may add 1 finely chopped zucchini in place of the peas if you like, or in addition to them. Make it your call!