Pat the tuna steaks dry with paper towels and season both sides with salt and pepper.
In a small bowl, combine the softened butter, capers, parsley, lemon juice, lemon zest, garlic, and a pinch of salt and pepper. Mix until well combined and set aside.
Once the skillet is hot, add the olive oil.
Carefully place the tuna steaks in the skillet and sear for about 1-2 minutes on each side for medium-rare, or longer if you prefer them more cooked.
Remove from heat.
To serve, place the seared tuna steaks on a plate and top each with a generous dollop of the lemon caper parsley butter.
Serve immediately with your choice of sides, such as a fresh salad or steamed vegetables.
Notes
For a spicier kick, add a pinch of red pepper flakes to the butter mixture.
You can also substitute the tuna with salmon or swordfish for a different flavor profile.