Step 1

Blend the strawberries until smooth then strain through a very fine sieve or cheesecloth to get as many of the seeds out as possible. Add the sugar, half at a time, tasting to see if it's roughly the sweetness you'd want then add more as needed.

Step 2

Divide the strawberry puree between two glasses, filling up to a little under halfway. Top the glasses with prosecco, a little at a time as it will bubble up a lot. Gently stir to mix and serve.