How to cook frozen cooked shrimp?

I'm trying to cook a meal for my mother in law but with the ingredients that we have at home: �frozen cooked shrimp, tomatoes, parsley, cilantro, garlic, olive oil, red pepper flakes, pasta, capers, parmesan. �The problem is the frozen cooked shrimp. �I have tried to cook with it before and the shrimp always ends up rubbery. �Any ideas?