Mash ½ garlic clove with a pinch of salt. Mix in 1 tablespoon of Dijon mustard, 2 tablespoons of red wine vinegar, and, slowly, 4 tablespoons of the tuna oil drained from 145g of canned tuna in olive oil.
Boil 8 new potatoes until tender, then toss them while warm with a spoonful of the dressing. Blanch 50g of green beans for 5 minutes and cool in iced water.
Boil 3 eggs for 7½ minutes. Cool, peel, and halve.
Toss the leaves of 2 Little Gem lettuces, the beans, 50g of pitted black olives, and the potatoes with most of the dressing.
Arrange on plates with 2 tomatoes, cut into wedges, and the eggs. Flake the tuna over and drizzle with the rest of the dressing.
