Updated: Feb 6
The word "casserole" tends to instigate eye rolls, but I happen to be a big fan of this stigmatized cooking category! Sure- we've all had a bad casserole (or seen one as the centerfold of a 1970's cookbook). There are those that are bland, grey, mushy, heavy and flavorless- even the doggies would turn their noses up at these scraps! But others are downright magical. As a mom, I really appreciate the humble casserole and I'm here to advocate for it. A good casserole checks all my boxes: they are make ahead, freezer friendly, able to feed a small crowd, good for leftovers, and DELISH. I also find them to be the perfect vehicles for sneaking undetected veggies and other nutrients into the tummies of my discerning young sons.
This Chicken Tetrazzini will have even the snootiest casserole nay-sayers changing their tune! It's made from scratch with lots of love involved- and you can taste the difference. Don't be intimidated by the lengthy process. Each step is simple and straightforward! To start, cook your pasta 'til al dente and strain. Spaghetti is the classic choice, but linguini would work well too. I then sauté onion and mushrooms with aromatics and a splash of wine- use the same pot for easier cleanup! Rotisserie chicken, peas, parsley and the cooked spaghetti then get added to the mushroom mixture and next it's time to make the white sauce. This is just a classic bechamel, beginning with an easy roux. The trick is to stir constantly and cook slowly. The sauce will thicken up within 10 minutes and then, off the heat, I boost the flavor with parmesan and lemon zest. Once the white sauce is ready, you pour it over the other ingredients and toss until everything is creamy and coated well. You can then transfer the mixture to one large baking dish, or two smaller ones- I will often go with two so that I have one for my freezer! All that's left is an easy breadcrumb topping and a 30 minute stint in the oven.
My tetrazzini is nostalgic but updated with fresh flavors for the modern kitchen. The whole family enjoyed this one! To be honest, I did have to pick out all the mushrooms from my 5 year old's portion, but he devoured everything else- and I got to enjoy bonus mushrooms so saw it as a win. If you're on the fence about casseroles, give this one a try! Meanwhile, I'm going to keep on converting you all to casserole disciples one recipe at a time. Enjoy!
prep time: 10 min. cook time: 50 min. - 1 hr. serves: 8
12 oz spaghetti (3/4 standard package)
5 tbsp butter, divided
3 tbsp extra virgin olive oil, divided
8 oz sliced mushrooms
1/2 yellow onion, diced
1 tbsp minced garlic
pinch red pepper flakes (optional)
1 tsp chopped fresh thyme
1/2 cup dry white wine
1 rotisserie rotisserie chicken, coarsely shredded
4 tbsp all purpose flour
3-1/2 cups 2 % milk
1 cup grated parmesan cheese, divided
1/8 tsp ground nutmeg
1 tsp lemon zest
1/2 cup chopped parsley, plus extra for garnish
1 cup frozen peas
1/2 cup panko bread crumbs
Preheat the oven to 375° and grease a 9" x 13" baking dish with some butter. Bring a large pot of water to a boil. Season the water liberally with kosher salt and add the spaghetti. Cook until a little shy of al dente, pulling it a minute before the package directs- about 10 minutes total. Remember, it will continue to cook in the oven as the tetrazzini bakes! Drain the spaghetti, rinse with cold water and set aside. Wipe out the pasta pot and return to the stove.
Heat 2 tbsp oil and 1 tbsp butter over medium in the same pot you used to cook the pasta. Add the onion and sauté 3 minutes. Add the mushrooms, garlic, chili flakes (if using) and thyme and sauté 5 min more, until they are tender and lightly browned. Pour in the white wine and allow to reduce almost completely. Season with 1 tsp kosher salt and some black pepper. Remove the mixture from the heat set aside too cool slightly.
In a medium sauce pot, add the 4 tbsp remaining butter and heat over medium to melt. Sprinkle the flour into the butter and use a whisk to stir until a golden paste is made. Reduce the heat too low. Cook this roux 2-3 minutes, whisking constantly, until pale golden. Slowly pour in the milk while whisking and add the nutmeg, 1-1/2 tsp kosher salt and 1/2 tsp black pepper. Bring the white sauce to a simmer, then reduce to low heat again. Simmer the sauce over low heat for 5-10 stirring frequently with a wooden spoon, until it has thickened significantly. The sauce should be thick enough to coat the back of the spoon when it's ready- run your finger through it, and if the line made on the spoon stays put it’s done. Off the heat, stir in the lemon zest and 1/2 cup Parmesan cheese to melt. Check for seasoning, adding more salt and pepper if needed.
To the pot with the mushrooms, add the chicken, cooked spaghetti, peas and parsley. Pour the white sauce over the mixture and toss with two spoons or tongs to coat everything evenly. Transfer the mixture to the greased baking dish, spreading it out in an even layer. In a small bowl, mix together the panko, remaining 1/2 cup parmesan cheese and 1 tbsp olive oil. Sprinkle this topping evenly over the tetrazzini. Bake, uncovered, until golden brown on top and bubbling, about 25-30 minutes. Serve hot with more parsley on top of desired.