Hotdish (which is usually written as one word, but sometimes as two) is a traditional one-dish meal in the Upper Midwest in states like Minnesota, North Dakota, and Wisconsin. There is no single hotdish recipe, but most of these casseroles contain protein, starch, and vegetable components and some sort of creamy (or cheesy) sauce that binds it all together. Hotdish recipes may call for a pie-like crust, though many cooks use alternative toppers such as tater tots.
Hotdish has its roots in Minnesota. The trend started during the Great Depression when people were looking for a cheap way to dress up canned soup, cheap meat and leftovers. Today, you can find hotdish year-round, but a just-from-the-oven casserole is best in the winter (which is a four- to six-month affair in the Upper Midwest). Minnesota's Saint Paul Winter Carnival has a hotdish contest where area chefs compete to make the tastiest version.