Cook your pasta in salty boiling water until al dente.
Meanwhile, tear up the bread, place it into some milk, and leave to soak for a couple of minutes.
Put the walnuts, garlic, and grated parmesan into a small food processor. Squeeze out the excess milk from the bread and add it to the other ingredients.
Add the olive oil, 4 or 5 Tbsp of milk or pasta cooking water*, and a generous pinch of salt and pepper. Blend them all together until well combined.
Taste and adjust the seasoning.
Drain your pasta and reserve 1 cup of the starchy cooking water.
Return the pasta to the pot, stir in the walnut sauce and add as much pasta cooking water as needed to thin out and give a nice and creamy texture to the dish.
Serve immediately with an extra drizzle of olive oil, freshly ground pepper and extra grated parmesan cheese you like.
This is one of those recipes where the quantities can vary, and adjusting the texture and the seasoning to your taste is quite easy.Cooking water: add pasta water gradually, you might not need all of it. You don't want to water down the flavor, but only make spaghetti nice and moist.*Milk or cream: If you prefer to keep this dish a bit lighter, blend the ingredients just using pasta cooking water, that's what I do most of the times. However, if you prefer a richer texture, you can substitute the pasta cooking water with milk (or even cream, if you like), they work just fine.Flavor: don't skip a drizzle of olive oil and freshly ground black pepper when you serve it, they really improve the flavor. You can also serve it with chopped walnuts on top, to add a crunchy texture, or with grated parmesan cheese, to add extra flavor!Pasta: you can use any short, large or long pasta shapes that work well to capture the walnut pesto sauce. I love spaghetti, but penne, fusilli, conchiglie work fine. Mini pasta shapes like orzo or even elbow macaroni don’t work well in the recipe.NOTE: Nutritional values are estimates only.