Preheat oven to 200˚C. Tear sourdough slices into rough bite sized chunks with your fingers.
Place in a bowl and drizzle with a good amount of olive oil until well coated. Season generously with salt and pepper. Toss.
Place bread chunks onto a baking tray and bake until deeply golden brown and crisp, turning half way through. About 10 minutes. Let cool.
For the main
Turn up oven to 220˚C with the fan on. Place mushrooms on a baking tray. Brush with olive oil and season with salt and pepper.
Roast for 7-10 minutes, depending on their size, until cooked through but still retain a good bite. Rest upside down on a cooling rack so they release their liquid.
For the dressing
Place egg yolk, 1 tbsp lemon juice, anchovies, Worcestershire sauce, garlic and parmesan in a small jug that can fit the head of a stick blender.
Start the blender and then slowly drizzle the neutral oil into the jug until you have a thick mayonnaise like emulsified sauce. Scrape into a medium sized bowl and slowly whisk in the olive oil.
Taste to adjust seasoning, adding the rest of the lemon juice, salt and pepper as needed.
For the salad
Wash lettuce leaves thoroughly and dry well. Place in a large bowl.
Add a drizzle of the dressing and gently toss the lettuce with your hands until well coated.
Add a sprinkling of grated Parmesan cheese and the croutons and toss again. Plate dressed lettuce onto a large serving platter / shallow bowl.
Slice the roasted mushrooms into large chunks and dot all over the salad. Serve with extra dressing on the side, a good crack of black pepper and enjoy!