Question: What do cottage pie and Corned beef pie have in common?

Context paragraphs:
Processed meat: Processed meat is considered to be any meat which has been modified in order either to improve its taste or to extend its shelf life.  Methods of meat processing include salting, curing, fermentation, and smoking.  Processed meat is usually composed of pork or beef, but also poultry, while it can also contain offal or meat by-products such as blood.  Processed meat products include bacon, ham, hotdogs, sausages, salami, corned beef, beef jerky, canned meat and meat-based sauces.  Meat processing includes all the processes that change fresh meat with the exception of simple mechanical processes such as cutting, grinding or mixing.

Corned beef sandwich: A corned beef sandwich is a sandwich filled with corned beef.  The salt beef style corned beef sandwiches are traditionally served with mustard and a pickle.

Corned beef: Corned beef is a salt-cured beef product.  The term comes from the treatment of the meat with large grained rock salt, also called "corns" of salt.  It features as an ingredient in many cuisines.  Most recipes include nitrates or nitrites, which convert the natural myoglobin in beef to nitrosomyoglobin, giving a pink color.  Nitrates and nitrites reduce the risk of dangerous botulism during curing by inhibiting the growth of "Clostridium botulinum" spores.  Beef cured with salt only has a gray color and is sometimes called "New England corned beef".  Often, sugar and spices are also added to recipes for corned beef.

Corned beef knot: The corned beef knot is a binding knot usually made in small line or string.  It gains its name by often being used for binding the meat of the same name while it is being cooked.  Since corned beef shrinks during cooking, the knot needs to be tightened several times during the process.

Corned beef pie: Corned beef pie is made from corned beef, onion and often thinly sliced, cubed or mashed potato.  It can be eaten hot or cold, making it a suitable common picnic food and also a 'winter warmer'.  The corned beef from which the pie derives its name may be leftover corned beef, as from a Sunday dinner, or tinned Bully beef.  The pie may be made with a mashed potato topping, as in Shepherd's pie, or with a traditional pastry crust.

Sloppy joe (New Jersey): In parts of northern New Jersey, a sloppy joe is a cold delicatessen sandwich.  There are minor variations depending on the deli, but it is always a double decker thin sliced rye bread sandwich made with one or more types of sliced deli meat, such as turkey, ham, pastrami, corned beef, roast beef, or sliced beef tongue, along with swiss cheese, coleslaw, and Russian dressing.

Pastrami: Pastrami (Turkish: "pastırma" , Romanian: "pastramă", Bulgarian: "пастърма") is a meat product usually made from beef, and sometimes from pork, mutton or turkey.  The raw meat is brined, partially dried, seasoned with herbs and spices, then smoked and steamed.  Beef plate is the traditional cut of meat for making pastrami, although it is now common in the United States to see it made from beef brisket, beef round, and turkey.  Like corned beef, pastrami was originally created as a way to preserve meat before refrigeration.

Shepherd's pie: Shepherd's pie (made with minced lamb or mutton) or cottage pie (made with minced beef) is a meat pie with a topping of mashed potato.

Bully beef: Bully beef (or corned beef in the United Kingdom) refers to the variety made from finely minced corned beef in a small amount of gelatin (bully beef; from the French "bouilli" "boiled"), and is sold in distinctive, oblong cans, just as in the United States and Canada, or in slices from supermarkets.  It is mainly imported from Argentina, Brazil, or Uruguay.  Bully beef and hardtack biscuits were the main field rations of the British Army from the Boer War to World War II.  It is commonly served sliced in a corned beef sandwich.  Hash and hotch-potch, in which potatoes and corned beef are stewed together, are also made.  Tinned corned beef is also used in mainland Europe.  Army bully beef rations were replaced in 2009 by mushroom pasta and halal dishes for troops stationed in Afghanistan.

New England boiled dinner: New England boiled dinner is the basis of a traditional New England meal, consisting of corned beef or a smoked "picnic ham" shoulder, with cabbage and added vegetable items, often including potato, rutabaga, parsnip, carrot, white turnip, and onion.  With a beef roast, this meal is often known simply as corned beef and cabbage.  A similar Newfoundland dish is called a Jiggs dinner.

Supporting paragraphs: Corned beef pie Shepherd's pie
Answer: mashed potato topping