Spinach Stuffed Shells with Truffled Bechamel

First make the stuffing for the shells. Heat the olive oil in a large saute pan and add the onions. Season with a pinch of salt and some pepper and cook on medium heat until softened and translucent in color, about 7 minutes. Add the garlic and spinach and cook until spinach is wilted. You may have to add the spinach in batches so it all can fit. Transfer the spinach mixture to a mixing bowl and let stand to cool a few minutes. To the spinach mixture, add the ricotta, Parmesan, and Beecher’s cheeses, and basil and mix. Taste and adjust seasoning with salt and pepper to taste. Then, after tasting, add the egg and mix to incorporate.
Take each shell and hold it in your hand, carefully keeping it open but being gentle as to not rip the delicate pasta. Spoon in a heaping teaspoon’s worth of the filling into the middle of the shell, and then gently squeeze the shell together to keep its form. Repeat with reamining shells and filling.  Place the stuffed shells in a sprayed baking dish and now make the sauce. Melt the butter in a saucepan. Once butter is completely melted, add the flour all at once and immediately begin whisking the mixture. This is called making a roux. Cook the roux for 3 minutes — this is to cook the raw flour taste out — and then add the cream all at once. You’ll notice the roux will clump up when the cream is introduced — this is normal, don’t panic — just whisk the clumps out until it becomes nice and smooth. Slowly add the milk, whisking as you go. Again you’ll notice clumping and then the roux smoothing out. Once all the milk has been incorporated, add the parmesan cheese and take the sauce off the heat. Whisk in the cheese until its melted and well incorporated into the sauce. Taste it and adjust with salt and pepper to taste, then add the truffle oil. Spoon out the sauce on top of the shells, not completely covering them but giving a generous dollop of sauce on top of each shell and around the sides of each shell. Bake in a 350 degree oven for about 20 minutes, or until top begins to get golden brown. Serve.