Wash, hull and slice the strawberries. Place into a non-stick frying pan with sugar, vanilla and lemon juice. Stir over medium heat until sugar has dissolved. Bring to gentle boil, boil 6 minutes, stirring often (you should have 3/4 cup). Set aside 20 minutes to cool to room temperature.
Spoon the strawberry mixture into a food processor. Add butter and pulse until well combined. Transfer to an airtight container. Refrigerate 3 hours.
Strawberry butter is delicious spread on croissants toasted bagels, sour dough, , crumpets and scones.