Add the blackberry jam, jalapenos, dijon and lime juice to a blender or processor and blend until smooth. Set aside.

Heat a cast iron skillet over high heat for about 2 minutes.

Meanwhile generously rub the salt and pepper on both sides of the tuna steaks and along the sides.

Melt the butter in the skillet. Add the steaks to the skillet and sear for 1 minute and 30 seconds. Flip and sear an additional 1 minute 30 seconds.

Remove from the skillet and let rest a couple minutes. Drizzle with the sauce and serve.