Step 1

Preheat oven to 400°. Grease a 13x9" baking dish with 1 Tbsp. butter.

Step 2

Cook egg noodles in a large pot of boiling salted water, stirring occasionally, until very al dente, about 2 minutes. Drain pasta; let cool.

Step 3

Melt 4 Tbsp. butter in a large skillet over medium heat. Add onion and leek; cook, stirring, until soft but not brown, 8–10 minutes. Increase heat to medium-high and add mushrooms. Cook, tossing occasionally, until most of the mushroom liquid has evaporated, 4–6 minutes. Add wine and reduce until skillet is almost dry, about 2 minutes; season with salt and pepper. Stir in Worcestershire and thyme.

Step 4

Melt remaining 4 Tbsp. butter in a medium pot over medium-low heat. Whisk in flour and cook until roux is golden and looks shiny and smooth, about 2 minutes. Whisking constantly, add chicken stock and bring to a boil. Reduce heat to medium and add cream, cheddar, and hot sauce; cook, stirring, until cheese is melted, about 1 minute. Season with salt and pepper.

Step 5

Gently fold mushroom mixture, cream mixture, noodles, and tuna in a large bowl; taste and adjust seasonings if needed.

Step 6

Transfer tuna mixture to prepared baking dish. Press chips into casserole so they stand upright. Bake casserole until bubbly around the edges and chips begin to brown, 15–20 minutes. Zest one-quarter of the lemon over casserole. Let sit 5 minutes, then top with dill and chives.