Article: Pour the broth into a deep pot or saucepan and place it on the cooktop over high heat until it just begins to boil. Then, reduce the heat to take it down to a simmer. You can finish preparing your mustard greens while your broth comes to a boil.  Incorporate ½ a cup (75 g) of sautéd onion or cubed pork belly into your simmering broth to add even more flavor. For more traditional Southern-style greens, you can also make your own stock by simmering a whole ham hock in 10–12 cups (2.4–2.8 L) water for 2-5 hours. Grab 1-2 large bunches of raw greens and hold them under the faucet to wash away as much dirt or debris as possible. Mustard greens grow in the ground, so it’s important to make sure they’ve been cleaned properly before cooking and eating them. After rinsing your greens, give them a shake or pat them dry with a paper towel to absorb any remaining moisture.  If you’re cooking a lot of greens at once, it may be easier to swish them through a sink full of water to clean them all at once.  A couple big bunches of mustard greens will serve 2-4 people, depending on how hungry you are. Lay your freshly-rinsed greens flat on a cutting board and use a sharp knife to slice the light green stems off the bottom of the bunch. You can also simply tear them away by hand. The stems tend to be tough, which means they’re not good for eating.  Avoid taking off too much of the dark, usable part of the greens. After removing the stems, you’ll be left with a bundle of loose leaves roughly the same size as romaine lettuce or bok choi. You may need to push the greens down to the bottom of the pot with a wooden spoon to make sure there’s enough room for them. If they look like they’re going to overflow, put them in one handful at a time as they continue to cook down. Drop the greens into the pot quickly so you don’t burn yourself accidentally. Tender young leaves should only take about 45 minutes to cook down completely. Allow up to 1 full hour for tougher, more mature greens to soften up.  Stir the greens occasionally to keep them from clumping together. You’ll likely notice your greens cooking down quite a bit as they simmer. This is normal. Because of their tendency to shrink up, it may be a good idea to use slightly more raw greens than you think you can eat. Turn off the cooktop and pour out the remaining broth slowly. Transfer the cooked greens directly to a serving dish. For more traditional Southern-style greens, you can also leave them to stew in a few inches of the flavorful liquid they were cooked in, which is sometimes known as "pot liquor."  The pot will be extremely hot after sitting on the stove for so long. Be sure to use potholders to protect yourself from burns. Place your leftover greens in an airtight plastic bag or lidded container and stick them in the refrigerator. They should stay good for 4-5 days.

What is a summary?
Bring 4 cups (950 mL) of chicken or vegetable broth to a low boil. Rinse your mustard greens under a stream of cool water. Cut the stems off the greens. Add the greens to your simmering broth. Simmer the mustard greens for 45-60 minutes. Drain the liquid from the greens and serve them hot.