Zest 1/2 lemon in a glass jar and add the lavender buds and vodka.

Seal the jar with a lid and shake to get everything to mix well.

Place in a cool dark place for 2 nights, shaking it occasionally.

Once the two nights have passed, strain the liquid in a bowl using a cheesecloth to add an extra layer so that any dust from the lavender cannot end up in the final product.

Press on the solids to extract as much liquid as possible, then discard the dried stuff.

Now it's time to add your food colouring to reach the desired hue, but this step is optional. Add the simple syrup, cover and gently shake.

Store in a cool, dark place for up to a year, shaking it gently before each use.