Kumquats are quirky. With their diminutive size and cheerful color, they resemble miniature oranges. But nibble on a whole kumquat and it might surprise you. Whereas oranges and other citrus fruits have tart peels and sweet flesh, kumquats possess the reverse.
Even the kumquat's botanical lineage is a bit idiosyncratic. The kumquat (from kam kwat, "golden orange," in Cantonese), a native of China, has been cultivated throughout Asia for centuries. Botanists initially categorized the fruit as Citrus japonica, later re-classified it in a new genus, Fortunella, and most recently renamed it Citrus japonica.
Of the six kumquat varieties grown worldwide, only two are commercially available in the United States. The most common type, Nagami, is egg-shaped and has a rich orange peel. The less common Meiwa, which tends to be larger, rounder, and sweeter, is said to be the best kumquat for eating fresh.
Kumquats are the perfect size for eating in one bite--a refreshing burst of sweet-tart flavor--but they also add a bright, perky note to just about any dish. Try tossing thinly sliced kumquats into a farro salad, or dropping whole kumquats into a pot of braised duck legs for the last few minutes of cooking. I love to poach them in a syrup made from one part sugar and two parts water. When the fruits turn translucent, they're done and will keep for weeks in the refrigerator. Poached kumquats are terrific stirred into yogurt, plopped into a glass of prosecco, or swirled into vanilla ice cream.
Most kumquats have seeds, which can be a real bother to remove if you're slicing a large quantity. However, some people swear by eating the seeds, claiming they add a delightful crunch. There's also a long-held belief that each kumquat should be gently massaged between forefinger and thumb before being eaten. Perhaps we kumquat-aficionados are just as peculiar as the fruit we love.
Salmon with Kumquat Salsa and Sautéed Greens
This kumquat salsa would be excellent spooned over any fish. After you sear the fillets, while the skillet is still hot, toss in big handfuls of hearty greens such as kale, chard, or spinach. They'll cook quickly and make a wonderful accompaniment to serve alongside the fish. If you dislike cilantro, use chervil instead.
3 wild Alaskan salmon fillets, about 1/3 pound each
5 ounces kumquats, thinly sliced and seeds removed
½ small shallot, finely chopped
Pinch of ground cayenne pepper
Zest and juice of 1 lime
¼ cup extra-virgin olive oil
1/3 cup cilantro leaves, roughly chopped
3 cups hearty greens such as kale, chard, or spinach
Kosher salt and freshly ground black pepper
Season both sides of each salmon fillet with a pinch of salt and a few grinds of black pepper.
In a small bowl, combine the sliced kumquats, shallot, cayenne, lime zest, lime juice, 2 tablespoons olive oil, cilantro, and ¼ teaspoon salt. Stir well. Taste for seasoning and add another pinch of salt or teaspoon of olive oil, if needed.
Heat a cast-iron skillet over medium-high heat for 2 minutes. Swirl in the remaining 2 tablespoons olive oil, and then allow the oil to heat up for about 30 seconds. Carefully place the fish into the skillet, skin-side down, and cook for 3 minutes. It is tempting to nudge the fillets around and peek underneath them, but resist this urge so that the skin can crisp while the fillets cook. Flip the fish and cook for another 1 - 4 minutes, depending on the thickness of each fillet. Transfer the fish to a plate.
Add the greens to the skillet and sauté, stirring occasionally, until the leaves are bright green and tender, about 2 minutes.
To serve, spoon some of the kumquat salsa over the fish and sautéed greens.