Mushroom and leek tetrazzini is the ultimate creamy, cheesy comfort that is sure to become a family favorite. Make-ahead friendly and adaptable, this pasta bake is worth adding to your weeknight repertoire. 
Question: when does a plate of cheesy pasta ever not sound appealing? I’ve rediscovered my love for pasta lately after taking a bit of a hiatus (I was on a major farro and quinoa kick), and feel like I’ve been reconnected with my noodle-twirling roots.
Growing up Italian, my mom made homemade sauce, meatballs, and pasta every Tuesday night without fail. Her recipes never changed, but the excitement we felt for pasta night never dwindled. We twirled and slurped and sopped up any excess with fresh Italian bread and dispersed from the table with our hearts and bellies feeling full.
This pasta bake may not have the same nostalgia factor, but the comforting nature of it feels fondly familiar—like a hug in a bowl.
Most tetrazzini’s include either chicken or turkey (which you could certainly include), but this meatless version feels every bit as meaty thanks to the addition of plump cremini mushrooms. Leeks add a sweeter, more delicate flavor than traditional onions, which compliment the deeply savory ‘shrooms beautifully.
You can amp up the creaminess by using either cream cheese or crème fraîche (I personally prefer the tang of the latter). Lemon zest and juice cut through the richness of the dish, which is brightened up by a final flurry of fresh parsley. 
I hope this creamy, cheesy casserole brings you as much comfort and bliss as it’s brought me. It’s perfect for a cozy weeknight in, or for entertaining guests over the holidays. Serve with a hearty kale salad and some crusty bread and it’s like bringing the best of an Italian restaurant to the comfort of your own kitchen. Cheers!
- 8 oz. dry spaghetti
- 1 Tbsp. olive oil
- 1 lb. cremini (baby bella) mushrooms, quartered
- 1 large leek, sliced thin (white and pale-green parts only)
- 3 garlic cloves, minced
- 1 tsp. lemon zest, plus 1 Tbsp. fresh lemon juice
- 1 Tbsp. unsalted butter
- 1½ Tbsp. all-purpose flour
- 1¼ cup lower-sodium vegetable broth
- ¾ tsp. kosher salt
- ½ tsp. freshly ground black pepper
- ¼ cup crème fraîche or cream cheese
- ½ cup grated Parmesan cheese, divided
- ½ cup panko breadcrumbs
- 2 Tbsp. fresh chopped parsley
- Bring a large pot of salted water to boil. Add pasta; reduce heat to medium, and cook until noodles are al dente, about 8 minutes. Drain; place back in pot.
- While pasta cooks, heat oil in a large, high-sided skillet over medium heat. Add mushrooms and leeks; cook 6 to 7 minutes, stirring occasionally, until softened. Add garlic; cook 1 minute, until aromatic.
- Stir lemon zest and juice into mushroom mixture. Add butter; stir until melted. Add flour; cook 1 minute, stirring constantly, until smooth. Add broth, salt, and pepper; cook 3 minutes, stirring, until liquid begins to thicken. Stir in crème fraîche or cream cheese and ¼ cup Parmesan; stir until smooth, about 2 minutes.
- Pour mushroom and leek mixture into pot with pasta; stir to coat.
- Preheat broiler to HIGH. Transfer pasta mixture to a deep 3-quart baking dish coated with cooking spray. Top with panko and remaining ¼ cup Parmesan. Broil until top is golden, 2 to 3 minutes. Garnish with parsley.
I'm Jamie - A Registered Dietitian, recipe developer, and full-fledged foodie inspiring you to live deliciously. 
This was SO GOOD and simple. I swapped normal pasta for Ancient Harvest corn and quinoa, and it turned out perfectly. This is the third or fourth recipe that I’ve made of yours, and all of them have been DELICIOUS!! Thank you thank you.
Hi Paige—SO glad you enjoyed this recipe! It’s been a favorite around here this fall. Cheers!
This looks amazing Jamie! And someone could totally add leftover turkey if they wanted to! 🙂