Turn the oven to 360°F. Combine the flours in a bowl with bicarbonate and salt. Add the vegetable spread cut into pieces and knead using your fingertips until you get a sandy mixture. Add water and knead just as long as you get a smooth dough, then let it cool in the freezer.

Wash the peaches, cut them into thin slices and set aside.

Roll out the dough about 1/8-inch-thick and transfer it to a baking sheet or mat. You can previously divide it into 4 to prepare individual mini tarts, if you like.

Arrange the peach slices in an overlapping pattern and single layer in the center of the dough, fold the edge on the peaches. Sprinkle with brown sugar and seed mix.

Bake the rustic peach tart from 25 (individual) to 30 minutes (large one). Let it cool down on a wire rack before serving.