First, the croutons. Preheat your oven to 180°C (350°F). Spread the sourdough cubes on a baking tray. Drizzle with a little extra virgin olive oil, toss with your fingers, and season with a pinch of salt. Bake for 10–12 minutes, turning halfway, until they are golden at the edges and feel dry and crisp when you squeeze one. They should smell toasty and warm, like fresh bread.

Make the garlic oil. While the bread toasts, warm 80ml of extra virgin olive oil in a tiny saucepan over the gentlest heat. Add the minced garlic and let it infuse for about 2 minutes. You want it to smell fragrant, not brown or burnt. The oil should take on a faint, golden tint. Remove from the heat and set aside.

Build the dressing base. In a large, wide salad bowl, place the anchovy fillets. Using the back of a fork, mash them into a paste against the bottom of the bowl. Add the egg yolk, lemon juice, and Dijon mustard. Whisk everything together until it is smooth and pale. The paste should look thick and glossy.

Emulsify the dressing. Now, very slowly, begin to drizzle in the cooled garlic-infused oil. Whisk constantly with your other hand. The mixture will start to thicken and look creamy. You want a steady, thin stream of oil, not a glug. When all the oil is incorporated, the dressing should be thick enough to coat the back of a spoon. Stir in the grated Parmesan. Taste a tiny bit on the tip of your finger — it should be salty, sharp, and rich.

Prepare the lettuce. Cut the heads of cos lettuce lengthways, or tear the leaves into large, bite-sized pieces. The leaves should be dry and feel snappy when you bend them. Place them into the bowl on top of the dressing, but do not toss yet.

Bring it together. Just before serving, scatter the warm croutons over the lettuce. Using your hands or two large spoons, gently toss everything together. You want every leaf to be lightly coated in that creamy, anchovy-garlic dressing, and you want the croutons to be evenly distributed. The sound of the leaves crunching as you toss is a good sign.

Finish and serve. Transfer the salad to a serving platter or individual plates. Use a vegetable peeler to shave generous ribbons of Parmesan over the top. Finish with a final crack of black pepper and a whisper of flaky sea salt. Serve immediately, while the croutons are still crisp.