High and Fast

• Slow-cooker recipes typically call for cooking on low heat for 6 hours or more, but cooking fish, including orange roughy, requires a gentle touch. On the stove top, orange roughy cooks in under 10 minutes. In the slow cooker, cook it on high heat for 45 minutes to 1 hour. To determine doneness, pierce the middle of the fish with a fork. The flesh should be firm, opaque and flaky, but still slightly moist. Do not overcook it, which will dry out the fish out.

It's in the Sauce

• Orange roughy benefits from a moist cooking method, such as braising or poaching, which is what a slow cooker is designed for. Add enough liquid to the slow cooker to partially cover the fish but not submerge it. Try white wine, soy sauce, citrus juice or broth. Top the fish with your favorite seasonings -- salt, pepper, dill weed, thyme, capers and grated lemon zest all work well.

Extra Credit

• Because orange roughy is naturally leaner than beef, chicken or pork, it's a good idea to spray the slow cooker with non-stick cooking spray before you add the fish. If the orange roughy sticks to the stoneware insert, it may tear as you try to remove it. You may want to heat the liquid to a simmer in the microwave or in a saucepan before you add it to the slow cooker; this speeds up the cooking time even more.

While You Shop

• A delicious meal of orange roughy starts with careful shopping. Look for orange roughy with a firm, elastic skin and a fresh scent. Avoid fish that's slimy or has a strong fish odor. Keep in mind that orange roughy sometimes contains high levels of mercury, according to the Monterey Bay Seafood Watch. The fish has been heavily fished in some areas, and the fishing practices used to catch it have caused environmental damage.