Bring a large pot of salted water to the boil and add the linguine. Cook for +- 10 minutes until al dente.
Meanwhile, in a large sauce pan, fry the mushrooms and leeks until all the liquid from the mushrooms have evaporated and the mushrooms have started to brown (+- 5-7 minutes). Add the garlic and oregano and fry for another minute.
Add the cream and lemon juice and season to taste.
Drain the linguine, reserve 1 cup of water and add to the sauce. Add a few tablespoons of the pasta cooking water and toss to coat the linguine in the sauce. Serve with extra cracked black pepper and a few oregano leaves.