I've attempted to make a cheese sauce 4 times...the first 3 I didn't realize what I was doing and did not cook the roux at all...so it was grainy.
Today I used butter and flour (though I think it was a 1:1.5 ratio), let it simmer for 5 minutes until slightly pasty, added milk, and let that mixture simmer for about 8 minutes until it was a medium yellow (not quite golden, as the butter+flour mixture was.) Then, I turned the heat to low, stirred in an egg, an added the cheese a 1/4 cup at a time. The only cheese I used was mild cheddar.
I've read all the posts I could find here on the subject, and tried to use every suggestion I came across, but it's still grainy. What am I doing wrong?