Carroty Mac and Cheese

Preheat oven to 400°F and grease an 8-inch square baking pan. Arrange a rack in the top third of the oven.

Cook macaroni according to package instructions in a large pot of salted boiling water; add carrot 3 minutes before pasta is finished cooking; drain well.

While pasta is hot, stir in all but 1/2 cup of the cheddar and the butter. In a bowl, whisk together the sour cream, milk, eggs, salt, mustard powder, and pepper. Fold mixture into the pasta.

Scrape the mixture into the prepared pan.

Sprinkle the remaining cheddar and the parmesan over the top.

Bake until the casserole is firm to the touch and golden brown, about 30 minutes.

What Else?

•If you're grating your cheddar cheese in the food processor, you don't have to wash out the machine before grating the carrots. Or vice versa.•This is one of those macaroni and cheeses with an eggy custard base that puffs as it cooks, and is cut into squares to serve, like a casserole, as opposed to that gooey, creamy, stove-top béchamel sauce version. I know that some people have strong opinions about proper mac and cheese (I'm an equal opportunist myself), but thought I'd let you know what you're getting.•Feed this dish to the kids as is; grown-ups should indulge with a squirt of fiery Sriracha or other hot sauce all over the top.•You can vary the cheese to give this rather plain (if tasty) dish more personality. Gruyère, aged Cheddar, pecorino, and aged Gouda will all add a sophisticated allure that will raise it above mere kids' food.