Tonnato Sauce

Add the drained tuna, anchovy fillets, rinsed capers, lemon juice, and white wine vinegar to a blender. The quality of the tuna is the ceiling of this sauce — use the best oil-packed tuna you can find; water-packed tuna produces a grainy, dull result. Blend on high for 60–90 seconds until the mixture is completely smooth. There should be no visible tuna flakes, anchovy pieces, or caper skins. At this stage the mixture will be thick, blond-beige, and intensely savory — almost overwhelmingly salty and sour before the mayo is added.

Add the mayonnaise to the blender with the tuna base. Blend on medium speed for 20–30 seconds until completely combined — do not over-blend at this stage, as the mayonnaise can break under prolonged high-speed blending. The sauce will transform from the stark, too-salty tuna paste into something considerably more rounded, creamy, and pale. The mayonnaise provides the emulsifying structure, fat, and body that ties everything together. Scrape down the sides and blend for 5 more seconds if any unmixed mayo is visible.

Transfer the sauce to a bowl. Stream in the olive oil while whisking by hand — this adds a final layer of richness and adjusts the consistency. The olive oil will loosen the sauce slightly; add only as much as needed to reach the consistency you want: thicker for spreading on a platter of sliced veal, thinner for drizzling over roasted cauliflower or boiled eggs. Season with salt (taste first — the tuna, anchovies, and capers carry a great deal of salt) and white pepper. Taste and adjust acid if needed. Refrigerate immediately; tonnato sauce keeps for 3 days and is always served cold.