Vegetable Shepherds Pie

1. For the topping, heat the oven to 450F. Bake the potatoes on a foil-lined sheet until tender, about 45 minutes, then cool slightly and peel. Press through a ricer, food mill or colander into a large bowl, add the butter and stir until smooth. Stir in milk and season to taste.
2. For the filling, soak the dried porcini in 3 cups hot water and set aside. Put the lentils, 1 garlic clove, 1 tsp salt and 4 cups water in a medium saucepan. Bring to the boil, lower the heat and simmer, stirring now and then, until the lentils are tender but not mushy, 15 to 20 minutes. Drain and discard the garlic.
3. Heat 3 Tbsp oil in a large heavy pot over medium heat. Add the onions and cook, stirring occasionally, until soft, about 12 minutes. Add the chopped garlic, cook for 1 minute, then stir in the tomato paste and cook, stirring constantly, until caramelised, 2 to 3 minutes.
4. Add the bay leaves and wine, scraping up any browned bits. Stir in the porcini, pouring in the soaking liquid slowly and leaving the sediment behind. Bring to a simmer and reduce by half, about 10 minutes. Stir in the broth and cook, stirring occasionally, until reduced by half again, about 45 minutes.
5. Strain the mixture into a large saucepan and bring to the boil, discarding the solids. Dissolve the cornstarch in 2 Tbsp water, stir it in and simmer until thickened, about 5 minutes. Whisk in the soy sauce, season with salt and pepper and set aside.
6. Heat the oven to 450F again. Toss the vegetables and pearl onions with the remaining 2 Tbsp oil, 5 garlic cloves and the rosemary in a large bowl, season and spread over 2 rimmed baking sheets. Roast, stirring once, until tender, 20 to 25 minutes. Lift out the garlic cloves, mash well and stir into the sauce. Discard the rosemary. (Lentils, sauce and vegetables can be made a day ahead; cover separately and chill.)
7. Spread the lentils in an even layer in a 3-quart baking dish set on a foil-lined sheet. Toss the roasted vegetables with the fresh mushrooms and chopped herbs and layer over the lentils. Pour the sauce over the top, then spoon the potato evenly over everything.
8. Bake until browned and bubbling, about 30 minutes, then let it stand for 15 minutes before serving.

Tips from the ZestyPlate Kitchen

• Build the gravy on dried porcini and red wine; that's where the savoury depth lives.
• Stop the lentils at just tender so they hold their shape rather than turning to mush.
• Roast the vegetables before they go in to concentrate and caramelise their flavour.
• Drag a fork across the mash to make ridges, which crisp into golden peaks in the oven.