The Tohono O'Odham in southern Arizona harvest this fruit every year.
6 to 10 red-ripe prickly pear cactus fruits (tuna)
1/2 cup lemon juice
4 1/2 cups granulated sugar
1 (3 fluid ounce) package liquid fruit pectin
You should have enough fruit to make 3 1/2 cups of juice. Carefully remove thorns
from fruit by wiping with a paper towel and then brushing with a vegetable brush
under water. Put fruit in a saucepan with enough water to cover. Boil for 15 to
20 minutes. Pour off water and discard. Mash or puree fruit through a strainer lined
with doubled cheesecloth. Strain juice into a large measuring cup. Let juice sit
for at least 30 minutes to allow sediment to settle to the bottom. Pour off juice
carefully. You should have 3 1/2 cups.
In a saucepan combine fruit juice, lemon juice and sugar. Bring to a boil and
boil 1 minute. Stir in pectin and boil for 1 minute longer. Remove from heat. Stir
and skim foam off the top. Spoon into sterilized jelly jars and seal.