Begin by preparing the olive oil brioche. In a mixing bowl, combine 150g flour and 5g yeast. Mix, then add 75ml of water, one egg, and 30ml of olive oil. Knead until a smooth dough is formed. Let it rise in a warm place for 1 hour, until doubled in size. Punch the dough down and form it into a small loaf or individual buns. Bake at 180°C for 20 minutes, or until golden brown. Cool on a wire rack.

While the brioche is resting, prepare the tuna confit. In a small pan, place 80g of tuna, 5ml of olive oil, and 5g of chopped anchovies and 1 clove of garlic. Gently heat on a low setting for 15 minutes. Then, remove from the heat, add 10ml of lemon juice and 2g of chopped parsley, and allow to cool slightly. Gently flake the tuna and combine with all ingredients.

Boil 1 egg for 8 minutes to achieve a soft-boiled consistency. Cool under cold water, then peel and halve. Cook 70g of potatoes until tender, about 15 minutes. Similarly, cook 40g of green beans until crisp-tender, about 6 minutes.

Assemble the dish: Slice the olive oil brioche and lightly toast. Arrange the cooked potatoes, green beans, and 50g of halved cherry tomatoes artfully on the plate. Add the flaked tuna confit, then the sliced boiled egg and 20g black olives. Drizzle 5g mustard over the assembled salad components. Serve immediately.