This is a sweet and savory tart. The butternut squash is naturally sweet without any sugar and the austere sage pairs beautifully with butternut as well as with walnuts. Other than the sage, I used very few seasonings; just some cayenne pepper and salt. —dymnyno
Peel the butternut squash, seed it and cut it into 2 inch cubes.
In a large bowl add the brown sugar, cayenne pepper, and olive oil. Add the cubed squash and toss to coat all sides. Put on a baking sheet in a 350 degree oven for about 45 minutes until the squash in slightly caramelized.
To make the crust: Put the walnuts, butter, sugar, sage leaves and 1 egg in a food processor and process until it becomes completely mixed together. You will have to scrape down the bowl several times. Press the dough into a 11 inch tart pan with a removeable bottom. Bake in a 350 degree oven for about 10 minutes to set the crust.
In a medium sautee pan, add a little olive oil and when hot, add the onions, sage and minced garlic and cook until slightly soft.
Remove the caramelized squash from the oven and cool a bit. Put the squash, onion , garlic and sage mixture, 3 eggs, 4 tablespoons cream into a food processor and process until smooth.
Pour the squash mixture into the cooled walnut crust and smooth the top. Bake in a 350 degree oven for about 45 minutes. Watch for the top of the tart to darken, but don't let it get too dark.
Remove from the oven and cool a bit. Garnish with fried sage leaves. (Froth some egg white and dip and then fry in a little olive oil) OR make some savory whipped cream with just heavy cream, sage leaves and a pinch of salt.
Note: The fried sage leaves are delicious, but they get a little soggy if left on the tart, so make them fresh just before serving.