In a pan, add butter and melt on low heat until it starts to show bubbles.
Now add all-purpose flour and a quick stir. Make sure the heat is low.
Cook the butter and flour until it becomes aromatic.
Now add pour a glass of milk and quickly stir to make a thick mixture.
Season with salt, pepper, and paprika.
As the sauce starts to get thick and forms a smooth texture then
Add cheese and give it a quick stir.
Continuously stir the sauce until it forms a blended smooth texture.
Thickens the sauce on low flame as per your desired requirements.