Mango Coconut Macadamia Conserve

4 cups diced mango, from about 7 mangoes (Tommy Atkins or Ataulfo/Champagne variety)

2 cups (14 ounces) sugar

Juice of 1 lemon

¼ teaspoon freshly grated nutmeg

1 cup (about 2½ ounces) unsweetened flaked (not shredded) coconut

1 cup roasted, salted macadamia nuts (about 4¾ ounces), coarsely chopped

½ teaspoon unsalted butter, optional

Bring a large pot of water, deep enough to cover the jars, to a boil over high heat. Place a rack in the bottom of the pot; use a tea towel if no rack is available.

Place 3 small plates and 3 teaspoons in the freezer for testing the set (see note). Wash the jars, lids and rings and place them on a towel near the stove. Have at the ready a ladle, bubbler (or nonmetallic knife) and damp towel.

Combine the diced mango, sugar, lemon juice and nutmeg in a 5-quart, heavy-bottomed, nonreactive pot. Stir well to begin dissolving the sugar, but delicately to preserve the individual pieces of mango.

Slowly increase the heat to high, bringing the mixture to a strong boil. It will be foamy and active. Stir regularly to keep the mixture from sticking or scorching. Once the foam begins to recede, in about 40 minutes, check the set via the cold plate test, using a spoon and plate from the freezer. If the conserve is not set to your satisfaction, continue to cook it for 3 or 4 minutes and test again. Repeat until the jam is set.

Stir in the coconut and macadamia nuts; return the conserve to a boil, then remove from the heat.

To clear the last of the foam, add the butter, if using, and stir well. Ladle the conserve into the jars, leaving ½ inch of head space. Run a bubbler around the jar, removing air bubbles. Wipe the rims and threads of the jar with the damp towel. Place the lids and tighten the rings.

Lower the jars into the boiling water bath. Process for 15 minutes, starting the timer from the moment the water returns to a boil. After processing, remove the jars from the water bath and set them upright on a towel to cool naturally over 12 hours.

Remove the rings, test the seal and wash the jars well. Label the jars; store the jam in a cool, dark place for up to 1 year.

Cook's notes: You'll need a ladle, a bubbler (or nonmetallic knife) and a damp towel, and jars with new lids and rings. For the cold plate test, remove the jam from the stove to avoid overcooking. Remove a plate and spoon from the freezer. Dip the spoon into the jam and spoon a small amount onto the cold plate. Push against the now-cold jam. It should give slightly but should not be runny. This should not be a hard-set jam but a slumping jam.

Water-bath canning safely seals high-acid, low-pH foods in jars. The time for processing in the water bath is calculated based on the size of the jar and the consistency and density of the food. For safety's sake, do not alter the jar size, ingredients, ratios or processing time in any canning recipe. If moved to change any of those factors, simply put the prepared food in the refrigerator and eat within a week.

The conserve can be stored at room temperature for up to 1 year. Refrigerate after opening. Before adding the nuts, taste one. Rancid nuts are horrible, and putting them in jars is disastrous.

Makes 3 half-pint (8-ounce) jars, plus one 4-ounce jar.

Nutrition values per 2-tablespoon serving: 120 calories, 5 g fat (2 g saturated), 19 g carbohydrates, 1 g fiber, 18 g sugar, 0 protein, 0 cholesterol, 20 mg sodium.

Cathy Barrow for The Washington Post