Cooking greens, those mainly from the brassica and amaranth families, either delights or confounds us. Some folk claim they’d eat collards, kale, or spinach, at every meal, and with equal or greater zeal, those from the opposing camp would sooner perish than have to eat--lo, even smell--a pot of stewed mustards or chard. For the dissenters, those who have lost hope in their abilities to cook with healthy vegetables, and those who are simply wary of working with greens for the first time, there are a few simple principles to follow that will give you myriad successes as you explore the culinary possibilities this chlorophyllic pantheon holds.
Cooking time: all greens have different cooking times, which is very important to identify. Many who have been repulsed by the smell of overcooked brassica greens are experiencing the release of sulphur through elongated heating. To avoid this, pay attention to the structure of the greens you’re dealing with. It’s rather intuitive, as delicate plants such as spinach and chard only need a brief amount of heating, whereas tougher leaves like collards need increased time to become tender.
The relative toughness of each green’s stem will determine how you process the greens. If the stem is very hard (think bok choy, collards, kale) it needs to be removed, chopped finely, and sauteed ahead of adding the leafy parts.
Size of the leaves
Large leaves need to be cut into small pieces. Adding really large leaves to your cooking implement, whether it be a pot or a saute pan creates a lot of wasted space, and as the greens cook, they become increasingly more difficult to stir, as the will wrap around you spoon or tongs. Smaller pieces also ensures more surface area, and therefore shortened cooking times. You don’t want to end up with half your greens cooked, and the other half raw because it’s taking too long, and you aren’t able to redistribute them evenly as they wilt.
Method of cooking
All greens can be stewed, and if that’s all you wish to do, so be it. By following all the previous principles, you will be sure to have evenly cooked, delicious greens that are not mushy, and retain many of their healthy vitamins and minerals. But sturdier greens can be cooked at high heat for an added crispy/crunchy character. While spinach should be cooked very briefly in some kind of fat and potentially even some good stock, the tougher brassica greens (collards, kale, brussels sprout leaves) can be cooked so that they become golden brown around the edges, elevating their flavor by adding sweet and toasted notes. The same principle can be applied when cooking with Brussels sprouts and flower sprouts. If you have really big leaves, they can even be grilled over charcoal, propane, or wood!
Greens will wilt readily when they are exposed to the air as they lose moisture. It is easy to confuse this process as a result of being exposed to heat, but the quality of greens depreciates fast even in the refrigerator. Make sure they are mostly dry before storing in ziploc bags or large plastic tupperware with the lid cracked. They may benefit from a damp paper towel being introduced to either method of storage, as this will aid in the preventing the moisture loss. Be sure that they do not sit in a puddle of water.