Combine water, sugar, and mint in a medium saucepan.
Bring to a boil, stirring constantly; reduce heat to medium, and cook, stirring constantly, until sugar dissolves.
Remove from heat, and set aside.
Remove leaves and stem ends from pineapple.
Peel pineapple, and trim out eyes; remove core.
Chop half of pineapple, and set aside; cut remaining half into chunks.
Place pineapple chunks in bowl of a food processor.
Add mint mixture.
Process until smooth.
Combine pineapple puree, chopped pineapple, and crushed strawberries in a saucepan.
Cook over low heat just until thoroughly heated, stirring frequenrly.
Transfer to a serving bowl, and srit in lemon juice.
Serve warm or chilled over ice milk or angel food cake.
Refrigerate any remaining sauce for larer use.