Samantha Okazaki / TODAY
- 1 pound orecchiette (or shells, spirals, etc)
- 2 tablespoon olive oil
- 1 small onion, finely diced
- 4 ounces mushrooms, finely diced
- 3 tablespoons all-purpose flour
- 1 cup whole milk
- 1 cup chicken stock
- 1 1/2 cups grated white cheddar cheese, divided
- Salt and pepper
- 1 12-ounce can solid white tuna (packed in water), drained
- 1 cup frozen peas
- Preheat the oven to 425 degrees.
- In a big pot, cook the pasta for three minutes less than instructed on package (should be slightly under al dente because it will continue to cook in oven). Drain and set aside.
- In the same pot, heat olive oil over medium heat. Add mushrooms and onions, and sauté for 5 minutes or so, until they begin to caramelize. Add flour, stir, and sauté for another minute.
- Whisk in chicken stock, then milk and then 1 cup of the cheddar cheese. Bring to a boil, whisking constantly, and then lower to a simmer and whisk constantly until sauce begins to thicken, between 5-7 minutes. Season to taste with salt and pepper. Remove from heat and stir in tuna and peas. Add pasta and stir, season again to taste with salt and pepper. Place in a baking dish, and sprinkle with remaining cheddar cheese. Bake uncovered for 15-20 minutes, until top gets bubbly and golden.
- While it's baking, slice the white and pale green parts of leeks very thinly. Rinse under water in a colander.
- Heat about an inch of vegetable oil in a small pot over medium heat. Add leeks and fry for roughly 10 minutes, stirring frequently to prevent burning. Once golden, remove with a slotted spoon and place on a paper towel. When casserole is done baking, sprinkle the top with the crispy leeks.