French Lentil Terrine with Savory Carrot Custard

Heat the oven to 325°F and arrange a rack in the middle. Bring 8 cups of the water to a simmer in a large saucepan over high heat; keep at a simmer.Meanwhile, bring the remaining 1/4 cup of water to a simmer in a large frying pan over medium heat.

Add the carrots and 1/2 teaspoon of the salt and season with pepper. Reduce the heat to medium low, cover with a tightfitting lid, and cook until softened, about 5 minutes. Using a slotted spoon, transfer 1/2 cup of the carrots to a small bowl and transfer the remaining carrots to a blender, leaving any excess water in the pan; set both aside. Wipe out the pan and set aside.

Place 1 cup of the cream and the egg in the blender with the carrots and blend until smooth, about 30 seconds. Evenly divide the carrot-cream mixture among 6 (1/2-pint) tempered-glass jars. Divide the reserved 1/2 cup of carrots among the jars. Evenly space the jars in a 13-by-9-inch glass baking dish.Being careful not to get water inside the jars, add enough of the simmering water to the baking dish so that it reaches just past the carrot mixture in the jars. Cover the baking dish tightly with aluminum foil and carefully transfer it to the oven.

Bake until the outer 1 inch of each custard is set (the centers will still be slightly jiggly), about 25 minutes. Meanwhile, sauté the leeks and zucchini and cook the lentils.

Heat the olive oil in the reserved frying pan over medium heat until shimmering.

Add the leeks and thyme, season with salt and pepper, and cook, stirring occasionally, until just starting to soften, about 5 minutes.

Add the zucchini, season with salt and pepper, and stir to combine. Cook, stirring occasionally, until the zucchini is crisp-tender and the leeks are completely softened, about 4 minutes more.

Remove the pan from the heat and set aside.

Place the lentils, bay leaf, and garlic in a medium saucepan and cover with cold water by 2 inches. Bring to a boil over high heat. Reduce the heat to medium low and simmer, stirring occasionally, until the lentils are still slightly hard in the center, about 10 minutes.

Add the remaining teaspoon of the measured salt, stir to combine, and continue to simmer until the lentils are just tender, about 3 to 4 minutes more.

Drain through a large fine-mesh strainer.

Remove the garlic clove and bay leaf and transfer the lentils to a medium bowl.

Add the chèvre and the remaining 2 tablespoons of cream and stir to evenly combine; set aside.When the carrot custards are ready, carefully remove the jars from the hot water and transfer to a wire rack to cool slightly, about 10 minutes.To assemble the terrines, divide all of the lentil-chèvre mixture over the carrot custards, using your fingertips to gently smooth it into an even layer. Divide all of the leek-zucchini mixture over the lentil-chèvre mixture.

Serve warm or at room temperature, or let the terrines cool completely, cover tightly, and refrigerate for up to 3 days.