Boil the pasta and set aside.Heat ½ tablespoon butter in a pan and saute the chopped vegetables. Remove to a plate.Add 1½ tablespoons butter in the same pan and add maida/flour. Whisk very well.Add boiled milk and mix well. Whisk very well in low flame to avoid lumps.Once the sauce starts to thicken, add salt, pepper powder, chilli flakes and dried herbs. Mix well.Cook further in low flame till the sauce thickens and turns smooth.Add sauteed veggies and mix well.Add boiled pasta and mix well.Serve white sauce pasta hot.