Cook the noodles just until al dente, according to package instructions.
Sauté the veggies: Melt 1 tablespoon butter in a large skillet. Add celery, onion, peas and garlic and sauté for a few minutes. Set aside.
Make Sauce: Add remaining 3 tablespoons butter to the pan. Once melted, add the flour and cook, stirring, for 1 minute. Slowly whisk in the chicken broth and milk until smooth. Bring to a simmer and stir constantly, until slightly thickened. Reduce heat to low and add salt, dill, lemon juice, parsley, and 1/2 cup parmesan cheese. Taste and add additional seasoning, if needed.
Combine: Remove from heat and stir in the pasta, vegetables and tuna. Pour mixture into a 9x13’’ or similar size baking dish. Sprinkle with remaining 1/2 cup of parmesan cheese.
Add Topping: Crush ritz crackers and add melted butter. Sprinkle mixture over the casserole.
Bake at 350 for 25-30 minutes. Store leftovers in the refrigerator for up to 5 days.
Video
Notes
Tuna: Choose good quality canned white albacore tuna. Cracker Topping: you could also use crushed potato chips, breadcrumbs, cornflakes or your favorite crackers.Make Ahead Instructions: Sauté the veggies, make the sauce, and cook the noodles. Store everything in separate containers in the fridge until ready to assemble the tuna casserole.To Freeze: Cook the noodles so they are slightly undercooked. Follow the recipe and assemble casserole (don't add cracker topping) in a freezer-safe container or disposable aluminum pan. Cover well and freeze for up to 3 months. Thaw overnight in the refrigerator then sprinkle with crushed crackers and bake until hot and bubbly.