Cook Arborio rice in vegetable stock for about 18-20 minutes until tender.

In a pan, melt butter and sauté chopped onion and garlic until translucent.

Stir in tomato paste and cook for 2 minutes.

Combine cooked rice, sautéed mixture, Parmesan cheese, fresh basil, and lemon zest in a bowl. Mix well and let cool.

Once cool, fold in mozzarella cheese.

Form the mixture into balls and coat each with flour, beaten eggs, and breadcrumbs.

Heat oil in a deep pan and fry the arancini until golden brown on all sides.

Drain on paper towels and serve with Calabrian chili aioli.