Add olive oil to a pan over medium high heat. Once the pan is heated add shrimp, olives, peppers and capers. You want to warm these ingredients slightly. Once these are nicely warmed through, add garlic, parsley and red wine vinegar. Reduce the heat to medium, and cook for another five to seven minutes. You’re just looking to marry all these flavours together. Turn heat off and set pan aside.
While ingredients in the pan are cooling, cut a slit in the middle of the tuna steaks making sure not to slice all the way through. You’re making a pocket for the filling.
Once the filling is cool enough to handle, stuff each steak with equal amounts and season with salt and pepper.
In a small food processor combine all the ingredients for the sauce and pour into a small sauce pan gently heat over medium heat.
When you are ready to cook the tuna, heat a skillet over medium high heat and cook each steak for about two to three minutes per side (depending on how you like your tuna - cook for even longer on each side if you do not want your tuna medium-rare).
Serve tuna with a generous amount of the sauce and enjoy.