This hearty recipe from Zimmy’s Nook is a modern take on a comforting casserole with all the bells and whistles plus plenty of veggies, woven into the recipe in the most delicious — and imperceptible! — ways.
Bring a large pot of salted water to a boil. Add the cauliflower florets and potato cubes. Return to a boil, then lower the heat to a simmer. Cook for 8 minutes until the cauliflower and potatoes are soft. Use a slotted spoon or spider strainer to remove the cauliflower & potatoes from the water and place in a full-size blender.
Using the same pot and water, add the pasta and bring back up to a boil (adding more water if required). Lower the heat to simmer and cook the pasta for 2/3 of the package recommended time (do not cook fully). Drain the pasta and rinse under cold water. Strain and set aside. Return the pot to the stove.
While the pasta cooks, carefully place the lid on the blender and blend until cauliflower & potatoes are mostly smooth.
Combine the milk and stock together in a saucepan or microwaveable container and warm through.
In the drained pasta pot, add 3 tablespoons of olive oil, along with the flour. Stir over a medium heat until smooth and cook for 1 minute. Gradually pour the warmed liquid, 1/2 cup at a time, into the flour paste in the pot, stir until smooth before adding next portion of liquid. Once all the liquid has been added, simmer over medium-low heat for 2 minutes (mixture will remain relatively thin, not saucy).
Pour the hot contents of the pot into the blender with the cauliflower mixture and add the Dijon mustard. Ensure the lid stays on and blend until silky, smooth, and thick. Season to taste with salt and black pepper.
Preheat the oven to 335°F convection bake (350°F regular bake).
In a 5 quart (12 inch) ovenproof skillet or sauté pan, heat the butter over a medium heat. Add the mushrooms and cook, stirring occasionally until beginning to shrink and release liquid (about 5 minutes). Add the garlic, thyme, chili flakes and a pinch of salt to the frying pan, turn the heat down to low and cook for 1 minute. Add the Spinach + Bok Choy to the pan, cover with a lid and steam for 3-5 minutes until the greens have wilted. Remove from the heat.
Add the pasta to the pan and toss to coat. Add the sauce and stir to fully combine sauce, pasta, mushrooms & greens.
Mix the topping ingredients in a small bowl and sprinkle over the pasta. Place the pan into the oven and bake for 25-30 minutes until the sauce is gently bubbling and the topping is slightly browned.
If desired, turn on the broiler for the last 3 or 4 minutes for a crispier top… but watch carefully and do not let it burn!!
Divide between bowls and serve hot.