Boil 2 cups of water in a saucepan.
Add the fettucine into the boiling water with 1 tbsp vegetable oil and little salt.
Drain the fettucine when it's 3/4 th cooked.
Heat 1 tbsp butter in a pan,add mushrooms and toss on high flame.
Add green Capsicum, black pepper and white vinegar and saute for 5 mins.
Transfer this to a bowl and keep aside.
To the same pan, add 1 tbsp butter,add garlic and toss.
Add plain flour and milk simultaneously and keep stirring without forming lumps.
Add more milk if required to adjust the consistency.
Add grated cheese and mix.
To this saucr add boiled fettucine and sauteed mushrooms and bell peppers.
Mix well and sprinkle dried oregano,red chilli flakes and salt for taste.
Toss well and serve.