In the summer months, blueberry and lingonberry bushes carpet the forest floor. Both bushes can be so abundant that a comb-like ‘spade’ is often used to sweep through them to gather up the fruits into a basket or bucket. This ‘spade’ is commonplace in most Nordic homes located anywhere near a forest. Small and sweet, forest blueberries differ from the South American farmed blueberries now available all over the world. Their flavour is much more concentrated and sweeter, and this pie is a great way to eat them: gooey, warm and with a little salty, crunchy crust – you can’t go wrong. Don’t be deterred though, fresh or even frozen berries from anywhere will cook into a marvellous filling. If you do use frozen ones, the pie will need a little longer in the oven.