Step 1

For polpette, heat 2 tbs oil in a frypan over medium heat. Add onion and cook, stirring, for 3-4 minutes until softened. Add garlic and cook for a further 1 minute or until fragrant. Remove mixture from pan and set aside to cool.

Step 2

Place breadcrumbs and milk in a large bowl and set aside for 5 minutes to soften. Add cooled onion mixture and remaining ingredients, and stir to combine. Shape into walnut-sized polpette.

Step 3

Place on a baking paper-lined baking tray and chill for 30 minutes to firm up slightly.

Step 4

Heat remaining 2 tbs oil in a large frypan over medium-high heat. Add polpette and cook, turning, for 4-5 minutes until browned all over. Remove from pan and place in a large ovenproof dish.

Step 5

Preheat the oven to 220°C. For the sauce, return pan to medium heat.

Step 6

Add oil and onion, and cook for 3-4 minutes until softened.

Step 7

Add the garlic and cook for a further 1 minute or until fragrant.

Step 8

Add the tomato paste and cook, stirring, for 30 seconds to coat. Add pasta sauce, thyme, beef stock and beans, and bring to a simmer. Reduce heat to low and simmer for 8-10 minutes until slightly reduced. Pour over meatballs, then scatter over mozzarella.

Step 9

Bake for 8-10 minutes until cheese has melted. Top polpette with basil leaves and serve with garlic bread on the side.