-
1
Heat the oven to 350 degrees F. Butter an 8-by-8-inch glass baking dish, and bring a large pot of salted water to a boil.
-
2
Heat the olive oil and 1 tablespoon of butter in a medium saucepan over medium heat.
-
3
When the oil is hot and the butter foams, add the celery and cook, stirring occasionally, until soft but not browned, about 5 minutes.
-
4
Stir in the scallions and jalapeno and cook for 3 minutes more.
-
5
Add Old Bay Seasoning and flour to the vegetable mixture, stirring until the flour is well incorporated.
-
6
Cook for 1 minute, then slowly pour in the milk, stirring well to make sure no lumps of flour remain.
-
7
Bring the mixture to a boil, reduce the heat to medium low, and simmer, stirring occasionally, until the mixture thickens slightly, about 5 minutes.
-
8
Remove from the heat, taste, and adjust the seasoning with salt and freshly ground black pepper.
-
9
Stir in sour cream and mustard, and set aside.
-
10
Once the water is boiling, add the egg noodles and cook until just tender (cut open a noodleit should have a white core running through the middle), about 3 minutes.
-
11
Drain.
-
12
Stir 3/4 cup cheddar and the egg noodles into the vegetable-and-milk mixture.
-
13
Flake the tuna into the mixture and stir gently to combine.
-
14
Pour into the prepared baking dish and set aside.
-
15
Combine the parsley, 2 tablespoons of butter, 1/4 cup of cheddar, and the saltine crumbs in a mixing bowl, using your hands to mix well until all the butter is incorporated.
-
16
Sprinkle this mixture evenly over the casserole.
-
17
Bake for 20 to 25 minutes, or until the crackers are golden brown and the casserole is bubbling.
