Mix diced pineapple, sugar and lemon juice in a heavy saucepan.
Bring to a boil over medium high heat and then reduce heat to between medium-low and medium, stirring occasionally.
Continue cooking and stirring occasionally for about 30-35 minutes or until liquid is reduced and fruit is golden in color.
Remove from heat. If a smoother consistency is desired mash with a potato masher or blend with immersion blender. Allow to cool before placing in jars.
Cover and refrigerate for up to 3-4 weeks.
Notes
Fruit may be left in chunky diced pieces or blended afterwards with potato masher or immersion blender if a smoother consistency is desired.
5.5-6 cups of diced pineapple will yield approximately enough preserves for two 8 ounce jars.