If blue Hubbard squash is not around your neighborhood, look for Tahitian squash, Kabocha, buttercup, or any of the very sweet and flavorful winter squashes. To cook any winter squash into a puree, seed and peel it and cut the flesh into pieces. Simmer the squash in a heavy-bottomed pot with about 1 inch of water and a little salt, tightly covered, until it is falling apart. Lift the lid and give it a stir now and then, adding a little water if necessary. When the squash is completely tender, remove the lid, raise th heat, and stir constantly as you cook away all the excess moisture. Then mash the pulp with a potato masher or puree it in a food processor. The finished puree should have the consistency of a thick applesauce. Another method is to roast squash in the oven.

Heat the milk in a medium-sized saucepan and whisk in the semoline, cornmeal, and 2 teaspoons of butter. Continue stirring with a whisk or a wooden spoon until the mixture thickens, then remove it from the heat, let it cool for about 5 minutes, and whisk in the beaten eggs a little at a time.

Stir in the squash puree, the molasses, 1/2 teaspoon of salt, nutmeg, and cinnamon. Whisk all this together or process it in a blender for a few seconds-the mixture should be silky smooth, with no lumps. Taste, and add more salt if needed.

Peel and quarter the onion and slice it rather thickly. Saute the onion in a tablespoon of butter with the ginger and a dash of salt until it begins to color. Lower the heat and keep cooking the onion until it is an even caramel color.

Stir the walnut pieces and the crumbled cheese gently into the squash mixture; the cheese should not get too mushy and blend into the custard, but rather should stay in distinct lumps. Pour the mixture into a large, shallow buttered baking dish, and scatter the sauteed onions over the top. Put the flan into a pre-heated 400 degree oven; after 10 minutes, lower the heat to 350 degrees and bake for 40-45 minutes more.

Serve the flan hot or warm, with some Chipotle Sauce on the side.