You could let the heavy cream and lavender infuse for 30 minutes, and then re-heat it before adding to the white chocolate when making the ganache.
A lot of people have issues when making white chocolate ganache. Here are some tips to help:
- Make sure to use good quality white chocolate, don’t use white chocolate chips, or candy melts. To be considered white chocolate, it must have at least 20% cocoa butter. - You can add 2 tbsp of butter to the ganache after incorporating the heavy cream. This will help make the ganache smooth and stable.
- Do NOT over heat the chocolate because it will separate and curdle. - If you place the ganache in the fridge, and it becomes too hard, you can always whip it with a mixer.