take a wide pan, add water in it & place on a high flame.
add salt and oil in it. leave the water for boiling.
till the time water boils, take oats and grind them to fine powder. keep aside.
when the water begins to boil, add pasta in it and let it boil on medium heat.
keep stirring occasionally otherwise pasta may stick to the bottom of pan.
when pasta turns soft, switch off the flame and pass the water carrying pasta through a sieve. immediately pour some cold water over the hot pasta to stop it's cooking process.
take another pan and add butter in it. put on low flame and let butter melt completely. add oats flour (prepared at no. 3 above) to the butter.
roast oats flour for 1 to 2 minutes but don't let the oats turn brown.
add milk while stirring into the pan simultaneously otherwise lumps will be formed.
add salt and black pepper. keep stirring.
when the mixture turns thick and start sticking to spatula, it is ready. stop cooking it anymore.
add boiled pasta and finely mix.
your white sauce pasta without maida is ready. serve hot after garnishing with roughly crushed black pepper and chilli flakes.