Strawberry collins

Method

1. Rinse the strawberries under cold running water, then pick off the green tops. Slice and put in a medium saucepan with the water.
2. Bring the water to the boil, then reduce to a medium simmer and let the strawberries cook for 15 minutes. Skim and discard any foam that rises to the top.
3. Strain the strawberry liquid through a fine sieve into another clean saucepan (discard the strawberries). Add the sugar then bring back to the boil, stirring to help dissolve the sugar. Simmer the syrup for 5 minutes until the sugar is completely dissolved, skimming any additional foam that rises to the top.
4. Remove from the heat and allow to cool completely. Pour into a container, seal and refrigerate.
5. To make the cocktail, rub a lime wedge around the rim of a highball (collins) glass, then dip in salt. Fill the glass a third of the way up with ice then pour over the mezcal, lime juice and strawberry syrup. Give it a stir and top up with grapefruit soda.