Preheat the oven to 350ºF. Line a 9x5 loaf pan with parchment and set aside.
In a large skillet, sauté the carrots, mushrooms, shallot and garlic until carrots are tender, about 5 minutes. Season with salt and pepper and transfer to the bowl of a food processor.
To the processor add remaining ingredients, reserving 1/2 cup lentils, and process until a dough starts to form. Pulse in remaining lentils.
Transfer dough to the prepared loaf pan, pressing it down with a wooden spoon or spatula. Smooth the top and prepare the glaze.
Whisk all glaze ingredients together then pour over the loaf. Bake for 40 minutes, then remove and allow to cool for 5 minutes before slicing and serving. Remaining slices can be frozen or kept in the fridge for 2 - 3 days.