Make the lentils:
Heat olive oil in a large pot and sauté the onions over medium-high heat for 4 minutes, stirring constantly.
Lower heat to medium-low, and add in the carrots and celery. Cook for 10 to 15 minutes until soft. Stir in the garlic, bay leaves, thyme, rosemary, and parsley and sauté for 30 seconds. Stir in lentils and pour in wine and stock. Let simmer 40 to 50 minutes until the lentils are soft. When the lentils have finished cooking, season to taste with salt and pepper and stir in tomato paste.
Make the mashed parsnips:
Meanwhile, peel and chop the parsnips into 2-inch chunks. Place chopped parsnips into a large pot of cold, salted water over medium heat. Bring to a boil, then lower heat slightly to simmer for 15 minutes, or until tender. Drain, let excess water dry off, then return to the pot with the almond milk, olive oil, and a large pinch of salt and a dash of black pepper. Mash until smooth, check seasoning, and set aside.
Assemble the pie:
Preheat the oven to 375°F and spoon the lentil mixture into an 8- or 9-inch pie dish. Top with parsnip mash. Bake 30 minutes or until the top is golden.
To make this dish ahead of time, assemble the pie, cover, and freeze for up to two months. When you're ready to make it, defrost and bake as instructed.