With the rack in the middle position, preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper.
On a floured work surface, roll out the dough to form a sheet ¼ inch (½ cm) thick, large enough to cut out two 8-inch (20 cm) circles. Place the dough circles on the baking sheet and prick lightly with a fork. Refrigerate.
In non-stick skillet over medium-high heat, soften the onions in the oil. Add the potatoes and brown over high heat. Add the garlic and cook for 1 minute. Season with salt and pepper. Let cool.
In a bowl, combine the cheese, tomatoes and potato mixture. Adjust the seasoning. Spread the topping over the dough circles.
Bake for 20 minutes or until the crust is golden.
Cut the tarts into wedges. Serve with a salad, if desired, and garnish with sour cream to taste. Delicious as an hors d’oeuvre.
Cut out the dough circles using a plate or the bottom of a cake pan as a guide.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.