Bring water to boil in a large pot with 1spoon salt add pasta and cook stir continuously.

Once cook drain pasta. Reserved this draining water for later use.

For veggies -
Heat olive oil/butter in a pan add chopped onions saute till soft add chopped veggies cook for 2-3 min. Turn off the flame transfer the veggies to a bowl keep them aside.

For pasta sauce-
Heat butter in the same pan adds garlic saute 30second add refind flour stir continuously till the raw smell of flour goes away now pour milk little by little and stir. Make sauce it does not lumps.

Cook until thicken add grated cheese mix well add sauteed veggies add boiled pasta if it thickens add reserved water mix well add black pepper powder red chilli flakes mix well.

You should take any pasta of your choice
Veggies are also of your choice.