This recipe makes a fabulous last minute meal. It comes together in under 10 minutes and tastes like it was made in a restaurant but only has a few ingredients.
Add the thinly shaved onion to a small bowl of cold water and set aside.
In a small mixing bowl, whisk together the olive oil, orange zest, orange juice, lemon juice and Calabrian chilies. Season with salt and set aside.
Arrange the slices of tuna on a serving platter. Drizzle the sauce over the tuna. Drain the slices of onion and arrange over the top of the tuna. Serve immediately, garnished with flakey sea salt.