Seared Tuna Steak with Soy SauceĀ Onions

February  9, 2021
1 Ratings
Photo by beckjohnson
  • Prep time 20 minutes
  • Cook time 40 minutes
  • Serves 1
Author Notes

Seared Tuna steak with roasted soy onions, rocket, pickled radishes, sweet sesame sauce and cashews. —beckjohnson

What You'll Need
  • For the tuna steak and the onions
  • 1 tuna steak
  • 2 tablespoons soy sauce
  • 1/2 garlic clove, crushed
  • 1/2 lime, juiced
  • 1 tablespoon sesame seeds
  • 1 tablespoon black sesame seeds
  • 1 large red onion, sliced widthways into 4
  • 2 tablespoons soy sauce
  • 1 tablespoon sesame oil
  • Black pepper
  • For the garnishes and sauce
  • 3 radishes, finely sliced
  • 50 milliliters Red wine vinegar
  • 1/2 teaspoon sugar
  • 1/2 packet rocket
  • 2 tablespoons rice wine vinegar
  • 1 tablespoon soy sauce
  • 1 tablespoon maple syrup
  • 1 tablespoon sesame oil
  • 1/2 garlic clove
  • 1/2 teaspoon ginger, minced
  • 1/2 red birds eye chilli, deseeded and finely sliced
  • 2 mint leaves, finely sliced
  • 1 tablespoon toasted sesame seeds
  • 1 handful roasted cashews, crushed
  • 1 handful crispy fried onions
  1. For the tuna steak and the onions
  2. Preheat the oven to 170 celsius (fan). Peel the onion, and cutting off the top and bottom. Cut the onion into 4 or 5, depending on the size. Cut parallel to the way you cut the top and bottom off. Each slice should be about 1.5-2cm thick.
  3. Lay the onions out on a baking sheet, pour over 1 tbsp sesame oil and 2 tbsp soy sauce. Make sure the onions are covered and grind plenty of black pepper on top. Bake for 20 minutes, then carefully flip halfway, making sure the onion segments to not detach.
  4. Make your pickled radishes (step one on the other part). Then marinade your tuna steak in 1/2 lime, 1/2 clove garlic (reserving other 1/2 for later) and the 3 tbsp soy sauce. Leave to rest until you're ready to fry it.
  5. Remove the onions when cooked (they'll be slightly brown on either side), and leave to come to room temperature whilst you cook your fish.
  1. For the garnishes and sauce
  2. Whilst your onions are in the oven, finely slice you radishes so that they are 1-2mm thin. Put them in a small bowl, covered in the vinegar and sugar and put in the fridge (ideally do this the night before, but its not necessary).
  3. Mix together all the ingredients for the dressing: 2 tbsp rice vinegar, 1 tbsp soy sauce, 1 tbsp maple syrup, 1 tbsp sesame oil, the other 1/2 clove garlic, 1/2 tsp ginger, 1/2 red chilli, and the 2 pieces of mint, along with a big grind of black pepper.
  4. When the onions are done, and are cooling, coat the marinated tuna steak in white and black sesame seeds. Put 1 tbsp sesame oil on a pan or griddle and sear the tuna steak for 2-3 minutes on each side so that it remains slightly pink in the middle.
  5. Take the tuna steak off the heat, leave to rest on a chopping board whilst you assemble your plate: Lay down a bed of rocket first, then carefully place the onions on top. Slice your tuna steak at an angle - cut into 4-5 pieces, and lay on top of the onions. Roughly lay the pickled radishes around the plate. Cover well in the dressing, then top with the crispy fried onions, crushed cashews and remaining sesame seeds. Grind some freshly cracked ground pepper over it and serve.

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1 Review

Jenny T. February 10, 2021
100 percent recommended. Double up, you will want to eat it all over again!