Step 1

Coarsely grate half an onion. Thinly slice the remaining 1½ onions.

Step 2

Make meatballs (see method below).

Step 3

Heat oil in a 6-litre (24-cup) pressure cooker over medium heat; cook meatballs, turning, for 2 minutes or until browned. Transfer to a tray.

Step 4

Add sliced onion to cooker; cook, stirring, for 5 minutes or until soft and golden. Add garlic; cook, stirring, for 1 minute or until fragrant. Add tomatoes, paste, stock, sugar, vinegar and the meatballs, then season well; secure lid. Bring cooker to high pressure; cook for 5 minutes.

Step 5

Quickly release pressure according to manufacturer's instructions; remove lid. Add risoni and olives; secure lid. Bring cooker to high pressure. Reduce heat to stabilise pressure; cook 7 minutes. Quick release pressure again; remove lid.

Step 6

Serve meatballs and sauce topped with remaining fetta and oregano leaves.

Step 7

Reserving 1 tablespoon oregano leaves to serve; chop remaining leaves.

Step 8

Combine chopped oregano, lamb mince, grated onion (from step 1), 125g fetta, the egg, breadcrumbs, cumin, cinnamon, currants and salt, using your hands to mix very well. Season with pepper.

Step 9

Shape ¼ cups of mixture into balls and place on a tray. Cover and refrigerate until required.