In the same pan,add butter on a low flame.
Once the Butter melts, add flour. Microwave 2.5 cups of milk for 2-3 minutes.
Stir continuously for 45 seconds, until the flour becomes pale yellow and cooked.
Add warm milk to the pan slowly, stiring it continuously.
Bring the sauce to simmer on a medium low flame. You will notice the sauce starts to thicken.
Now add in salt, garlic powder, onion powder, oregano and red chili flakes.
Add ¼ cup of freshly grated parmesan cheese. Turn Off the stove once the sauce is thick after simmering for about 10 -12 minutes.