Preheat your oven to 200ºC/180ºC fan.
Lightly grease your tart tins with a little vegetable oil.
Remove your pastry from the fridge and roll it out until it is very thin and slightly larger than your tin. I like to roll out the pastry between two sheet of cling film as this makes it easier to roll out to the desired thickness and also means I don't have any trouble with it sticking to the work surface or rolling pin. I also like to roll out each tart individually as this makes it much easier.
Carefully lift the pastry into the tart tin and ease it into the sides so that it is in full contact with the tin. If you accidentally make a hole then simply patch it up with a little spare pastry.
Trim off any excess pastry using a sharp knife or rolling your rolling pin across the top of the tin.
Use a fork to prick holes across the bottom and up the sides of the pastry. It's essential that the holes go all the way through to allow air to escape while the tart shell cooks otherwise the bottom will puff up and the sides will collapse.
Place the tins on a baking tray and pop into the oven for 12-14 minutes until just golden.
Once cooked remove the tarts from the oven, leave them in their tins for about 10 minutes to harden a little and then move them onto a wire rack to cool completely.
While the tart shells are cooling make your champagne ganache.
Put you double cream (1 tbsp) into a bowl.
Put your milk chocolate (75g) into a small saucepan and melt on a very low heat, stirring constantly until it has fully melted.
Remove the chocolate from the heat and add to the double cream. Beat the chocolate into the cream with a wooden spoon as quickly as you can (you have to work quickly to stop the chocolate going grainy). Once combined, add in the champagne (3 tbsp) a bit at a time, beat in each addition before adding more. You may want to taste as you go along, stop early if you're happy with the flavour or add a bit more if you think it needs it.
Once all of the champagne has been combined, pour the ganache into the cooled tart shells.
Top your tarts with the strawberries and serve.