Cut the tuna into 2.5cm / 1in dice. Peel the onions, leaving the root intact, and cut each onion
lengthways into 6 wedges.
Divide the fish and vegetables evenly between 8 wooden skewers (pre-soaked to avoid burning) and
arrange on the grill pan.
Mix the oregano and oil together in a small bowl. Season with pepper. Lightly brush the kebabs
with the oil and cook under a grill preheated to high for 10-15 minutes or until evenly cooked,
turning occasionally. If you cannot fit all the kebabs on the grill pan at once, cook them in
batches, keeping the cooked kebabs warm while cooking the remainder. Alternatively, these kebabs
can be cooked on a barbecue.
Garnish with lime wedges and serve with a selection of salads and cooked couscous, new potatoes