Start by boiling water on a pot and when the water has reached a boiling temperature pour the fettuccine noodles inside it, stir well and leave them boil.
In the meanwhile pour half of the olive oil in a pan and pour the finely chopped garlic and after 2 minutes add the sliced chestnut mushrooms, stir well and let them fry for about 5-6 minutes and when they are done place them in a bowl.
If the fettuccine noodles are boiled place them in a colander and then take a pan and pour in it the rest of the oil and fry the already cleaned shrimps for about 6-7 minutes.
Place the fettuccine noodles in a large bowl and pour on top of them the fried mushrooms and the fried shrimp with the oil you fried them in and stir well to distribute the sauce evenly. Serve the fettuccine with mushroom and shrimp sauce when they are still warm.