Grilled tuna fish

For the tuna belly: 

• Remove the tuna belly and clean it thoroughly.
• Make a   fried garlic oil with chilli pepper,strain, let it cool and put in a dispenser.
• Pour a bit of the fried garlic oil over the tuna belly and grill over high heat, searing first the flesh side and finish cooking the skin side.
• Take out the tuna belly in fillets and save. 

For  the piquillo pepper sauce:           

• Chop the garlic and piquillo pepper into brunoise, and the pickled  chilli pepper in fine rings.
• Make a fried  sauce with the soft olive oil and the garlic without browning it.
• Add the piquillo pepper and to finish, the chopped chilli pepper. Save.

For the garnish:

• Make some sliced roasted potatoes.
• When the potatoes and onions are done, drain off excess oil, season with salt and pepper and arrange them in layers on an oven tray, first the potatoes to be followed by the onion.Drizzle some white wine over the mixture and cook it briefly in the oven. 
• Cut the potatoes and onion with the help of a small round cutter.

 SERVING

• Place the sliced roasted potatoes on one side of the spoon.
• Put the tuna belly on top of the bed of potatoes.Let the layer be seen.
• Add the fried garlic oil with piquillo pepper.
• Sprinkle with parsley powder.
• Decorate with sweet potato chips and parsley powder.