- Separate the Swiss chard stems from the leaves. Cut the stems into ½-inch (1 cm) pieces and set aside in a bowl. Coarsely chop the leaves and set aside in another bowl.
- In a large non-stick skillet over high heat, soften the bell peppers and garlic in the oil for 2 minutes. Add the chard stems and cook for 4 minutes or until al dente. Add half of the chard leaves and cook until wilted. Add the remaining leaves and olives. Cook until all the leaves are tender. Season with salt and pepper. Keep warm.
- In another skillet over medium-high heat, sear the tuna in 1 tbsp (15 ml) of the oil for 1 to 2 minutes on each side or until nicely browned on the outside but still raw at the centre. Season with salt and pepper. Set aside on a plate.
- In the same skillet over medium-high heat, soften the green onions and chives in the remaining oil. Add the broth. Bring to a boil and let reduce by half.
- On a work surface, slice the tuna steaks.
- Divide the chard mixture among four shallow bowls. Top with the sliced tuna and green onion broth.