Heat the oven to 400°F.
Toss 6 chopped leeks and 2 chopped parsnips with the oil onto a roasting pan.
Sprinkle half the thyme leaves (3 TB) and season well with salt and pepper.
Roast for 30-35 minutes, until the leeks are soft, and parsnips are soft all the way through.
Once the leeks and parsnips have softened, remove from the oven.
While the veggies are baking, you can make the oat creme fraiche.
Place oats in a bowl and cover with hot water, so oats are submerged.
Let it rest for at least 30 minutes up to 1 hour. *(Longer and it will get slimy)
Drain and rinse the soaked oats in a fine sieve or strainer.
Add to a blender along with the 2 cups water, oil, and salt.
Blend for 3-5 minutes or until very smooth.
Pour the cream back through the fine mesh sieve or strainer.
Use a large spoon to gently press the liquid through the strainer.
Dispose of the oat gunk and pour the cream into a glass jar, leaving 1 cup out for the recipe.
Keep the remaining creme refrigerated for up to one week.
Mix all (but ½ cup) of the grated parsnips in a bowl with the oat cream, garlic, lemon zest, ACV, broth, and beans. *(Remaining ½ cup of parsnips is used for the topping.) Taste and season with salt and pepper.
Toss the leeks and parsnips with the bean and oat cream mixture.
Then put the entire mixture back onto the baking pan.
In a separate bowl, make the crumble topping.
Using your fingertips, rub the oats, oil, flour, and pumpkin seeds together.
Add the remaining ½ cup of grated parsnip and 3 TB thyme leaves.
Continue until it starts to clump together.
Sprinkle the crumble topping over the filling.
Optional: Sprinkle the cheese on top and return to the oven for 30 minutes.
Remove from the oven when done and let it sit a few minutes.
Enjoy warm, fresh out of the oven!