Step 1Heat the oven to 350 degrees.
Step 2Combine 2 cups of water, the lentils and 1 teaspoon of salt in a saucepan and bring to a boil. Reduce the heat and simmer the lentils until tender but slightly firm, 20 to 25 minutes. Drain and set aside.
Step 3Meanwhile, cut the tops off each squash and remove the seeds and pulp. Rub the inside and outside of the squash with oil and season with salt and pepper. Set the squash in a baking dish and bake until just tender, 40 minutes. Remove the squash from the oven and keep warm.
Step 1Heat the oil in a large skillet over medium heat and cook the onions, thyme, rosemary, bay leaves and salt until the onions are soft and browned, about 30 minutes.
Step 2Add the wine and garlic and reduce the liquid by one-half. Add the flour slowly, and cook for 4 to 5 minutes. Add the stock, bring to a boil, then reduce the heat and simmer until the liquid is reduced by one-fourth, about 25 to 30 minutes. Add the parsley.
Step 1Heat the oven to 350 degrees. Cut off the top one-fourth of the garlic and place the head on a piece of foil. Drizzle with 1 tablespoon of the oil and sprinkle with salt and pepper. Seal the foil and roast the garlic 30 minutes. When the head is cool enough to handle, squeeze the garlic from the cloves, cut into small pieces and set aside.
Step 2Cook the assorted mushrooms in the remaining 1 tablespoon of oil in a skillet over medium heat until softened, 5 minutes. Set aside.
Step 3Combine the cooked lentils with 2 cups of the Herb au Jus and the roasted garlic in a saucepan. Cook over medium heat, covered, until the lentils have absorbed most of the liquid and are tender, 10 minutes. Set aside.
Step 4Place each squash in the center of a serving plate or bowl and fill each with the lentils then the vegetables. For the sauce, combine the remaining Herb au Jus and the cooked mushrooms and heat in a saucepan until warmed through. Season to taste with salt and pepper. Drizzle the sauce over and around the squash.