Boil seafood mix in a bowl for 1-2 minutes. With boiled water. After that, drain them with a drainer and put them in another bowl.
Wash the mushrooms by putting them in a bowl full of clean water.
Using a knife, cut the chunks from the bottoms of the mushrooms and throw them away. Then, cut the mushrooms in half, and start slicing them into thin pieces. After that, put all of them in a bowl.
Put 2-5 teaspoons of butter and all of the crushed garlic in the pot. Heat for 1 minute. At the same time, fill another pot with water and start to boil in the meantime.
Chuck all of the sliced mushrooms in the pot and mix for 2-3 minutes. After that, pour the mushrooms in a bowl.
Using the same pot, put another 2-5 teaspoons of butter. Then, chuck all of the seafood mix in and mix for 2-3 minutes.
Chuck all of the mushrooms back in the pot and mix for another minute.
Pour a whole jar of creamy mushroom sauce into the pot and mix for 3-4 minutes.
Put 1/2 of the Fettuccine from the packet into the other boiling pot. Check on it every 2 minutes and if they're sinking in the water, stir them for 30 seconds.
Using the creamy mushroom jar, pour milk to fill in half a jar. Pour the milk into the pot and mix for 1 minute.
Put in only a handful of shredded cheddar and mix for 30 seconds.
This is the final process of cooking. Now put the amount of Fettuccine and sauce with seafood you want in a plate.
Get a fork and spoon on your hands, and enjoy! :)