Place the blueberries, sugar, 2 tablespoons of lemon juice and the zest in a medium saucepan over medium heat and cook for 2 minutes or until the sugar melts and berries soften just slightly.
Don't let the berries cook too long or they will become mushy and lose their beautiful shape.
Remove from the heat. Gently stir in the chopped mint.
To Make the Pancakes:
Whisk the ricotta and egg yolks together in a large bowl to combine, then whisk in the buttermilk.
Sift the flour, baking powder, and salt into the ricotta mixture. Stir with a whisk just until combined.
Using an electric mixer, beat the egg whites and sugar in a large bowl until stiff peaks form.
Using a large silicone spatula, gently fold the egg whites through the batter in 2 batches.
Gently fold the blueberries into the batter.
To Cook the Pancakes:
Melt some butter on a hot griddle pan over medium-low heat. Working in batches, ladle the batter onto the griddle.
Cook the pancakes about 3 minutes per side, or until the pancakes puff, become golden brown and are just cooked through.
To Serve the Pancakes:
Transfer the pancakes to plates. Spoon the warm blueberry compote over the pancakes.