Makes about 2¼ cups
- 1½ pounds fresh plums, pitted and cut into 1-inch pieces
- ¾ pound fresh strawberries, hulled and halved
- 2 cups sugar
- 2 tablespoon fresh lemon juice
- ⅛ teaspoon kosher salt
- In a large glass or ceramic bowl, combine all ingredients. Let stand at room temperature, stirring occasionally, until fruits have released their juices and most of sugar has dissolved, about 1 hour.
- Transfer fruit mixture to a medium enamel-coated cast-iron Dutch oven. Bring to a boil over medium-high heat; mash with a potato masher or the back of a wooden spoon. Reduce heat until mixture is gently boiling. Cook, stirring frequently, until thickened, about 50 minutes. Remove from heat. Let cool for 30 minutes. Spoon into jars. Cover and refrigerate for up to 2 weeks.