When the butter is melted, whisk in the flour and cook the mixture for about 1 minute. Continue to stir.
In a food processor, add the mascarpone and the peppers except for the reserved 3 peppers. Puree.
*You want to make sure to heat the milk slowly by adding a little at a time and the same goes for the cheese. This is a really important step so the sauce won't break.
*If you aren't into a mac 'n' cheese with texture, omit the ground almonds.