Two hours before making, place farro in a blender and pulse a few times to crack the grains slightly. You don’t want to create too much flour (or else you end up with porridge). Heat a large skillet over medium-low heat and toast the grains- a couple minutes until the color deepens a bit and you can smell the grains. Transfer to a bowl and cover with boiling water. 

While the grains are scalding, roast the acorn squash. I do this by cutting the squash in half, scooping out the seeds, and placing the squash face down in a braiser. Add ¼” water and cover. Roast in a 400˚F oven until tender, usually about 30 to 40 minutes. 

After two hours, drain the grains. Heat a braiser, or large skillet with high sides, over medium heat. Also, place the broth in a pot and heat. Add the olive oil and add the minced onions to the braiser. Cook until fragrant then add the drained grains and add enough of the hot broth to cover the grains. Cook, stirring occasionally, until the broth is absorbed. Repeat the process until the grains are tender, 30 to 45 minutes (see note). You might use only a part of the broth, you might use it all. 

While the risotto is cooking, scoop the cooked squash out of the skin and place in a blender all with the remaining ingredients for the puree. When the farro is tender and most of the liquid has been absorbed, stir in the puree and cook until thickened slightly and hot. 

Chop the parsley and lemon zest together until it’s well minced and combined. Sprinkle over the risotto and finish with the toasted hazelnuts, drizzle of olive oil, and parmesan.