Blueberry tart

This year I have the impression that there are more blueberries than in the past, and I bake more more fruits tart where I make a simple dough with a little of sugar for the pie crust and then just add fruits on top. I bake that for 20min at 190-200. It makes perfect simple desserts, tea-time sweets or breakfast. With blueberries I was worried that not adding sugar to the fruits might be a bit too sour, but the fruits are so ripe that actually sugar is not needed.  Actually I have noticed recently using less and less added sugar and salt to all my recipes and enjoying very much the result.