While your pastry sheets thaw, preheat your oven to 200°C. Finely dice your onion, spinach and grate your carrot.
In a large mixing bowl, add your sausage mince, onion, carrot, spinach and some salt and pepper to season.
Crush your two garlic cloves and add them to the rest of the mixture and combine well.
Spoon or pipe (using a piping bag without and end) onto the end of a pastry sheet. Depending on how thick you want your mixture inside your sausage roll will determine how much mixture you use.
Roll the pastry over the mixture. Then cut the rest of the pastry off using the side of the roll as a guide. This should leave you with enough pastry to do a second one. Approx half a sheet.
Cut your roll in half and then each half in half again. Then score each one twice and place on a well sprayed baking tray.
Base each one with milk, then place in the oven to cook for 30 to 40 minutes. Cooking time will vary depending on your oven.