Seared Tuna with Sweet and Sour Onions

Seared Tuna with Sweet and Sour Onions

10 minutes


20 minutes

4 servings

Seafood is my favorite protein to eat and to cook.  The key is not to overcook!  Tuna is best rare or even raw if using sushi grade tuna.  When preparing seared tuna, remove from the fridge and allow to sit at room temperature for 30 minutes or so.  Upon searing at high heat, the rare middle will not taste cold in the mouth. 


  • 1 large tuna steak, at least 1 inch thick, cut into 4 portions
  • Sea Salt
  • Freshly ground black pepper
  • 5 tablespoons of red wine vinegar
  • 1 tablespoon of sugar
  • 1 large red onion, cut pole to pole into thin wedges
  • Extra-virgin olive oil


  1. Season tuna on both sides with salt and pepper. Allow the temperature of the tuna to come close to room temperature. 
  2. In a small bowl, mix the vinegar, sugar, and a pinch of salt with 1/4 cup of water. 
  3. In a heavy-bottomed skillet (such as a cast iron), combine the onion with a little olive oil. Cook over medium-low heat, covered, until soft, about ten minutes.
  4. Add the sweet-sour mixture, stirring often as the liquid evaporates and the onions begin to caramelize. Transfer to a bowl.
  5. Clean the skillet, add 1 tablespoon of olive oil and raise the heat to high.
  6. Sear the tuna until well browned on both sides, but rare in center.
  7. Serve the tuna with the caramelized onions on top. Enjoy!

Article Provided By: Allison Thomas