Ius in Pelamyde Assa (Sauce for Baked Young Tuna) is a traditional Ancient Roman recipe for a classic sauce of spiced onions and raisins in a wine, stock, vinegar and olive oil base that's intended to be served with baked tuna. The full recipe is presented here and I hope you enjoy this classic Ancient Roman version of: Sauce for Baked Young Tuna (Ius in Pelamyde Assa).
Ius in pelamyde assa: piper, ligusticum, origanum, coriandrum viridem, cepam, uvam passam enucleatam, passum, acetum, liquamen, defritum, oleum, et coques. hoc ius convenit et in elixa. si vis, et mel addes.
Translation
Sauce for Baked Young Tuna: [Combine] pepper, lovage, oregano, fresh coriander, onion, seedless raisins, passum, vinegar, liquamen, defritum, olive oil and cook. If you wish, add some honey. This sauce may also be served with poached [tuna].
Combine the black pepper, lovage (or celery) seeds, oregano and coriander leaves in a mortar. Pound to grind then add the onion and raisins and pound again. Mix in the passum, defritum, vinegar, olive oil and fish stock. Turn into a small pan and bring to a boil. Reduce to a simmer and cook for 20 minutes, or until thickened.