Pan Bagnat (Nicoise Olive Oil Soaked Tuna Sandwich)

Split 1 small baguette lengthwise and press the crumb to form a shallow channel. Leave enough bread in place to support the filling after it absorbs the dressing. Whisk 2 tablespoons extra-virgin olive oil with 1 tablespoon red wine vinegar, then brush the mixture over both cut faces all the way to the edges. Thinly slice 120 g tomato and blot the slices with paper towel if they release a great deal of juice. Slice 40 g red onion just as thinly. Spread 120 g olive-oil-packed tuna, including some of its oil, over the bottom half of the baguette. Arrange 2 thinly sliced boiled eggs over the tuna so they cover the gaps rather than forming one thick pile. Add the tomato, red onion, 30 g black olives, 4 anchovy fillets, and 6 basil leaves in distinct layers. Distribute the olives and anchovies evenly because their saltiness is concentrated. Close the baguette, wrap it tightly, place a weight on top, and refrigerate it for 30 minutes to 2 hours. Pressing compacts the loose ingredients while the oil and vinegar season the crumb, which gives this Nice-style sandwich its cohesive texture. Unwrap it only after that rest. Cut with a firm, steady downward motion instead of sawing aggressively, so the soaked bread remains intact and the tuna, egg, tomato, and olives stay in their layers.