Instructions

1. Cut the tuna steaks into roughly 1-inch (2–3 cm) cubes.
2. Peel the red onions and cut them lengthwise into six wedges.
3. Seed the bell peppers and cut them into pieces similar in size to the tuna.
4. Slice the zucchini into thick rounds or half-moons.
5. In a small bowl, mix the olive oil, chopped oregano, and freshly ground black pepper.
6. Thread the tuna and vegetables alternately onto skewers, making about 8 skewers in total. Brush them generously on all sides with the oregano oil.
7. Grill over medium-high heat for 10–15 minutes, turning several times and brushing with additional marinade as they cook. The tuna should be lightly seared on the outside while remaining moist inside.
8. Serve immediately with fresh lime slices on the side.