Cook the egg noodles per the directions on the package, drain.
Preheat the oven to 350°F. Spray an 11x17-inch baking pan with non-stick cooking spray, set aside.
In a medium-sized bowl whisk together the mushroom soup, sour cream, milk, salt, and pepper until smooth.
Place the noodles, tuna, peas and carrots in a large bowl. Add the sauce and mix everything together until combined.
Pour the mixture into the casserole dish.
In a small bag add the crackers and crush them, place them in a small bowl and mix with the melted butter.
Sprinkle this mixture on top of the casserole.
Bake for 25-30 minutes until warmed through and bubble.
Top with optional parsley.