01 -
Grab a large pan and heat some olive oil with a couple spoons of butter over medium heat. Toss in the leeks, sprinkle on the sugar and salt, and keep stirring every now and then for 20 minutes until golden brown. If it dries out, splash in a bit of water to fix it.
02 -
Pour in the sherry and let it bubble until it’s almost gone. Scoop the leeks out of the pan and set those aside.
03 -
Melt the rest of the butter in the same pan. Spread the mushrooms out in a single layer and leave them alone for a few minutes so one side gets nice and brown. Flip them over and do the same on the other side, then season with some salt and pepper.
04 -
Add chopped garlic and sage leaves to the pan. Stir for a minute, then toss the leeks back in, along with the cream, balsamic vinegar, and lemon zest. Let it simmer until it thickens, which takes just a couple of minutes. Adjust the seasoning if needed.
05 -
While that’s happening, cook the fettuccine till it’s just right (al dente). Keep a cup of the pasta’s cooking water before draining it.
06 -
Take the sauce and toss it with the cooked fettuccine, pasta water, gruyere, and black pepper. Simmer for a quick 2 minutes until everything is melty and the noodles are coated completely. Taste and tweak the seasoning.
07 -
Scoop the pasta into four bowls and sprinkle pine nuts on top. Enjoy it on the spot while still warm.