The effect is subtle. The pasta won’t taste obviously of fennel, but the water carries a faint sweetness and perfume into the pasta. That background flavor quietly reinforces the fennel in the pan, the fennel seed in the sausage and the fresh fronds added at the end.
Give the pasta some room
A pound of orecchiette should be cooked in about 6 quarts of water. That may sound excessive, but these little ears have an annoying tendency to nest inside one another. When that happens, the exposed pieces cook while those trapped inside remain stubbornly hard.
A large pot of vigorously boiling water gives them room to circulate. Stir especially well during the first few minutes, when the surface starch is most likely to glue them together.
Not all orecchiette are alike
The pasta itself can change the dish more than you might expect.
The last time I made this, I used Barilla Al Bronzo, the company’s premium bronze-cut line. Its rough surface held the sauce beautifully, but the orecchiette remained surprisingly tough even after cooking beyond the time suggested on the package. There’s a difference between pleasantly al dente and pasta that seems determined to fight back along with the fennel.
For orecchiette, I prefer De Cecco. It still has enough surface texture to catch the sauce, but it cooks more evenly and becomes tender without losing the firmness that gives the little ears their character.
Whatever brand you use, treat the package time as a suggestion. Orecchiette are thinner at the edges and considerably thicker in the center. Taste several pieces and judge the middle, not merely the rim.
Let the mushrooms brown
Mushrooms need heat, room and a little neglect.
Spread them across the pan and leave them alone long enough to develop color. Constant stirring releases their moisture and turns the pan into a steamer. Browning begins only after that moisture has evaporated.
If the pan looks crowded, cook the mushrooms in two batches. It takes a few minutes longer, but the reward is a deeper, more concentrated flavor and mushrooms that remain distinct in the finished dish.
Save more pasta water than you think you’ll need
Many recipes mention reserved pasta water almost as an afterthought. Here, it’s an essential part of the sauce.