Prepare the sauce by whisking allingredients in a small bowl. Keep aside.
Take a non-stick frying or sauteing panand place on medium heat. A minute later rub the olive oil all-over the steaksand place the steaks in the pan. Season with the salt and pepper and sear forabout 2 minutes and until a bit of charring is created on the sides of thesteaks going up until ⅓ of their height. Flip over, season and sear as before.Remove from the heat and allow to rest for about 5’.
In the meantime, we prepare thecouscous by adding into a bowl the water along with the saffron, the lemonjuice. Stir well, add the couscous and the capers, drizzle with the oil stiragain and cover with cling film. Allow to absorb the water, 12-15’, uncover andadd the mint and scallions, season with the salt and mix well.
Slice the tuna steaks into 1 cmthickness, place on top of the couscous, drizzle with some of the sauce andsprinkle the sesame seeds. The remaining of the sauce can be kept for dipping.