Combine all ingredients except for the tuna in a medium bowl and whisk. Spices and powders should be evenly spread throughout the mixture.
Place the tuna steaks into a gallon Ziploc bag. Slowly pour the olive oil mixture (marinade) over tuna trying to get as much coated as possible. After all the marinade has been transferred, gently rub the marinade into the tuna on any areas not already covered.
Press out all the excess air and seal the Ziploc bag. Place in the fridge and let rest for at least 1 hour.
In a frying pan, place vegetable oil and allow to heat. Place the tuna in and allow to cook for 5-8 minutes on each side. The internal temperature should be approximately 90-95° Fahrenheit.
Let rest for 3-5 minutes then Enjoy!