Preheat your oven to 375°F (190°C). Bring a large pot of salted water to a boil.
Cook egg noodles for 2 minutes less than package directions indicate. Drain well but don't rinse.
In a large bowl, combine cream of mushroom soup and milk, whisking until smooth. Add garlic powder, dried dill, salt, and pepper.
Gently fold in the drained tuna, peas, diced onion, bell pepper, and 3/4 cup of the shredded cheese. Add the slightly undercooked noodles and toss until evenly coated.
Transfer the mixture to a greased 2-quart casserole dish.
In a small bowl, mix the crushed potato chips or panko with melted butter and sprinkle over the casserole. Top with the remaining 1/4 cup cheese.
Bake uncovered for 20-25 minutes until the edges bubble and the top turns golden brown.
Allow to rest for 5 minutes before serving to let the flavors settle and the sauce thicken to the ideal consistency.