Kumquats, with their sweet, orange-flavored rind and tangy flesh, are a lively match for tart cranberries in this stunning holiday tart. Look for firm, unblemished kumquats in the produce section in late fall and winter.
To make filling: Combine kumquats (or chopped orange), cranberries, 1/2 cup granulated sugar, currants, ginger and water in a saucepan and bring to a simmer. Cook over low heat until the fruit is tender and the mixture is thick, 3 to 5 minutes. Set aside and let cool to room temperature.
To make crust and bake tart: Place rack in lower third of oven; preheat to 350 degrees F. Coat an 11-inch tart pan, preferably with a removable bottom, with cooking spray.
Stir together flour, baking powder, baking soda and salt in a small bowl; set aside. Beat together 1 cup granulated sugar, butter, oil, egg, lemon zest and 4 teaspoons of the lemon juice in a large bowl with an electric mixer until smooth. Beat in the dry ingredients until completely blended. (Dough should be moist. Add a bit more lemon juice if it does not press together easily.) Turn the dough out onto a work surface and knead four or five times.
Divide the dough in half. Working through a piece of plastic wrap so the dough doesn't stick to your hand, evenly press half of the dough into the bottom and up the sides of the tart pan. Spoon in the reserved kumquat-cranberry filling and spread evenly.
Roll out the remaining dough on a floured surface into an 11-inch circle. Cut the circle into 1/2-inch-wide strips. Run a long spatula under the strips to loosen them. Lay half of the strips about 3/4 inch apart on top of the filling. (Don't worry if the strips break--simply piece them end-to-end. If the strips are extremely fragile, gather them up, knead them briefly, then reroll.) Lay the remaining strips diagonally across the first strips. Press the ends of the strips into the edge of the crust, removing any excess.
Bake the tart until the pastry is well browned, 30 to 40 minutes. Let the tart cool in the pan on a wire rack, covered with a clean towel to soften the top crust slightly. When completely cool, dust the top lightly with confectioners' sugar.
Equipment: 11-inch tart pan
1 starch, 1/2 fruit, 2 other carbohydrate, 1 fat