Not Chicken Tetrazzini

I started out attempting to make this recipe, Mustard Chicken and Orzo Casserole with Dill and Capers. However, the farther I got in the recipe, I the farther I strayed. It turned out I only had lemon herb seasoned chicken breasts, I didn't have enough fancy mustards and just had yellow deli mustard. I didn't have enough orzo or enough celery. I was explaining to Curtis how I had changed the recipe and his response was twofold: "Then I can call it chicken tetrazzini." and "At some point, you have to admit the man is bald." (as in, you've changed it so much, it's not the same recipe any more).

Despite all that, we liked it pretty well. I'll probably make it my way next time as well. It uses lots of fresh dill, which is why I chose it. This makes 4 - 6 servings.

Not Chicken Tetrazzini
based loosely on a recipe from Gourmet

3 c water
1 3/4 - 2 lbs chicken breasts (you can use lemon-herb marinated chicken breasts)
3 T butter
3 T all-purpose flour
3/4 c heavy cream
4 T mustard (yellow, dijon, and coarse-grain mustard or a combination)
3 T bottled capers, rinsed
1/2 t salt
1/4 t black pepper
1/8 t freshly grated nutmeg
1/4 - 1/2 c fresh dill, chopped
1/4 c sour cream
2 - 4 celery ribs, cut diagonally into 1/4" slices
1 c fideo (vermicilli) or orzo

Bring water to simmer in large heavy saucepan over moderate heat. Add chicken and simmer very gently, turning once, 6 minutes total. Remove pan from heat and cover, then let stand until chicken is just cooked through, about 15 minutes. Transfer chicken to a plate to cook and keep broth warm, partially covered. When chicken is cool enough to handle, shred with your fingers.

Melt butter in a 3 quart heavy saucepan over low heat, then add flour and cook roux, stirring, 3 minutes. Add warm broth all at once, whisking, and simmer gently, whisking occasionally, 10 minutes. Whisk in cream and simmer, whisking occasionally, 5 minutes. remove from heat and stir in mustards, capers, salt, pepper, nutmeg and dill (to taste). Transfer 1/2 c sauce to small bowl and stir in sour cream to make a topping. Set aside. Stir chicken into sauce (not the sauce with sour cream).

Meanwhile, cook celery and vermicilli in a large pot of boiling salted water, for 6 - 8 minutes. Drain. Stir pasta and celery into chicken mixture, then transfer to a gratin dish (or a 11 x 7 shallow dish), spreading evenly. Spoon sour cream topping over top and spread evenly. Bake, until heated through in a preheated 350 degrees oven, until sauce is bubbling around edges, 25 - 30 minutes.