This tart is perfect for breakfast, lunch or dinner or, maybe, even all three on the same day. Cavolo nero is also known as Lacinato or dinosaur kale. It is becoming ever more popular not only for its great taste but for its presumed health benefits too. The crust for this tart uses the idea of a shortbread crust to keep it tender while using whole wheat pastry and buckwheat flours. I like to serve the tart with a fruit salad of grapefruit supremes, toasted crushed hazelnuts and mint. While this has many healthy components they are just a nice side benefit to the decadence of this wonderful tart. —thirschfeld
Place the whole wheat pastry flour, buckwheat, parmesan, butter and salt into a large mixing bowl and stir it with a wooden spoon until it looks like a combination of cous cous and cornmeal. You may need to rub some of the bigger pieces between you hands to break up the butter.
Dump the crumbs into an 8 inch tart pan. Starting at the edges press the crumbs into the flutes. Use you index finger as a back stop by placing it at the top of the flute and pushing the flour up to it. Pack the crust tightly and evenly. Once you have finished the crust bake it in the oven for 20 minutes. Remove it from the oven.
While the crust is baking heat the olive oil and butter over medium heat in a 12 inch saute pan. Add the onions, anchovies and garlic. Season them with a little salt and fresh ground pepper. Saute them gently without coloring and until they are soft. You may need to adjust the heat and you will want to stir them to keep them from coloring.
Once the onions are soft add the Cavolo nero and toss and stir it to coat it with oil. Season again with a little salt and fresh ground pepper. Add the water and cover the pan. Let the Cavolo nero steam until tender but still vibrant in color, about 8 minutes over medium heat.
In a large mixing bowl combine the ricotta, parmesan and the eggs. Add a 1/2 teaspoon of salt and a few grinds of pepper and stir to combine.
Once the Cavolo nero is tender taste it and adjust the seasoning as necessary. Make sure all the water has simmered away from the Cavolo nero, you don't want it to be to wet. Let it cool for a couple of minutes and then add it to the ricotta and stir it well to combine.
Carefully spoon the filling into the tart and smooth and level it out. Place the tart into the oven and bake it for 50 to 60 minutes or until set and nicely browned.
When the top has browned remove the tart from the oven and let it cool to room temperature before cutting. Serve at room temperature.