Nope, there's no need to cook the peas. It's OK if the peas are still a little frozen when you mix this up. But to defrost the peas ahead of time remove the bag of peas from the freezer and place in the fridge. Easy! They'll defrost in no time. Sometimes if I'm in a big rush, I'll place the bag on the kitchen counter to defrost, but the fridge is the best option.