Pre-heat the oven to 180C(400F) and lightly grease a loaf pan.
In a bowl, combine the mince, onion, carrot, zucchini, oats, tomato sauce, herbs, garlic, salt and freshly-ground pepper. Use your hands to combine all the ingredients together until they are all evenly distributed.
Pack the mixture into the pan using your hands.
Cook the meatloaf for 1 hour or until it shrinks away from the sides of the tin.
Pour off any excess juices then leave to sit for 10 minutes.
Slice into 6 serves using a serrated knife and serve with salad or steamed vegetables.