What?
Are you crazy?
The peanut butter will metabolize with the protein in the cottage cheese rendering the protein not only useless, but now mutated into an agressive catabolic that seeks out amino acids and destroys them!
The remaining waste product is near impossible to pass through the kidneys, creating kidney stones and eventual kidney failure!
Don't mix the two, ever!
Obviously kidding ... hey, whatever floats your boat.
I personally mix 1 can tuna with a butt-load of cottage cheese, broccoli sprouts and flax oil almost every day - some get grossed out at it, but I can't get enough, especially knowing the protein and EFA benefits I'm ingesting!