Cook the noodles according to package in a large pot of salted boiling water, just until al dente (about 5-6 minutes). Drain.
In a large bowl, whisk together condensed soup and milk. Gently stir in the cooked noodles, tuna, and peas (if using). Taste and season with salt and pepper, if necessary. Can also add Mercy Chefs Cajun Joy or another Cajun seasoning during this step.
Transfer mixture to prepared dish. Sprinkle cheese on top then add crushed potato chips.
Bake for 20-25 minutes or until top is golden brown and inside is hot and bubbly.