Preheat the oven to 375 degrees and lightly grease a 9x13 baking dish.

Bring a large pot of water to a boil. Add the egg noodles and cook until just tender, then drain and return them to the pot.

Stir the cream of mushroom soup, milk, salt, and pepper into the noodles until evenly combined.

Fold in the drained tuna and frozen peas.

Transfer the mixture to the prepared baking dish and spread it into an even layer.

Place the crackers in a zip-top bag and crush them with a rolling pin until they form coarse crumbs.

Mix the crushed crackers with the melted butter, then sprinkle the mixture evenly over the casserole.

Bake for 20 to 25 minutes until the topping is golden and the edges are bubbling.