Cut the strawberries in half or in quarters if large, and put in a pan with the sugar and lemon juice. Heat gently until the sugar dissolves, then bring to a simmer. Cover the pan and cook the strawberries for 3 mins or until dark red and syrupy. Cool, then add the balsamic vinegar, if using. The compote can be stored in the fridge for up to 2 weeks.
Melt the lactose free butter gently in a small pan, then pour the clear yellow layer into a jug. Discard the white solids. Sift the gluten free flour and salt into a mixing bowl, and stir in the sugar.
Make a well in the middle, crack in the egg, then add the vanilla and a splash of lactose free milk. Whisk until thick and smooth, then whisk in the remaining milk. Put a few tbsp extra caster sugar in a shallow container, ready for sugaring the drop scones.
Heat a non-stick frying pan, then add a splash of clarified lactose free butter and swirl it around. Spoon in 4 dessertspoons of the batter, spacing them well apart, to make drop scones about 7cm across. As soon as bubbles appear on the surface, flip the scones and cook until puffed in the middle. Keep warm while you cook another batch. Toss the scones in the caster sugar, then serve with strawberry compote and a scoop of ice cream.