One of my favourite flavour pairings is salt and lemon. The tangy savory marriage makes any dish sing. With everything balance is key, making sure there isn’t too much of either. The salt perfectly rounds out the acidity of the lemon. With this recipe from Food and Wine I’d suggest you keep tasting the sauce before adding too much salt.
The beauty of flavour is that it’s subjective, allow the flavour to dance on your tongue and find your balance. As for the tuna go grilled vs broiled and a nice light veggie to compliment. Enjoyed with a wonderful Pinot Noir from Hubbs Creek, Wellington, Ontario.