Interesting. Let's look at the dream symbolism first:
Fish. Depending on the context of the dream, it can represent wealth, abundance or spirituality. In rarer cases, it *could* represent potential opportunities in love or projects ("there's more than one fish in the sea.")
Frozen. Things that are frozen have been put on ice for storage. In any case, whatever you have frozen is something that is not making progress but that you've kept for future use. These can be ideas, projects, financial opps or even potential mates/dates.
Trying to decide. You're obviously now considering your options.
Cook. Cooking, like eating, often symbolizes internalizing or incorporating the attributes of the food.
So reflect on how this information reflects what is going on in your waking life: Have you been contemplating different spiritual paths or different churches? Are you ready now to consider moving forward on some financial opportunities that you put on hold for a while? Or are you looking back to see which old flames you might revisit?