In a blender, process strawberries then press mixture through a fine mesh sieve over a bowl; discard seeds. In a saucepan, melt butter over medium heat. Pour in strained strawberry puree. Allow mixture to come to a boil & bubble until slightly thickened, about 6 minutes.
Cake
Melt white chocolate with butter. You can do it in the microwave with 30 second breaks or over a double boiler. Blend well.
Preheat oven to 375 F. Butter & flour 2 – 6 oz ramekins; set aside.
In a bowl, whisk together eggs, egg white, sugar, salt, vanilla, lemon juice & zest.