Katsuo-no-Tataki (Seared Bonito) with Mustard Sauce

• 2 packs, about 400 grams Katsuo-no-tataki (Seared bonito)
• 1 Sliced onion
• 1 slice Lemon
• 1 tsp Grain mustard
• 1 tsp Tomato ketchup
• 2 tbsp Soy sauce
• 2 tbsp Olive oil

1. The seared bonito I use is the type you can buy at the supermarket.
2. Mix together the seasoning ingredients, and feel free to either pour it over the bonito, or use it as a dipping sauce.

packs, onion, lemon, grain mustard, tomato ketchup, soy sauce, olive oil

Taken from cookpad.com/us/recipes/146059-katsuo-no-tataki-seared-bonito-with-mustard-sauce (may not work)