Preheat oven to 350°F. Grease the inside of the loaf pan with oil. Line the loaf pan (9-inch x 5-inch) with parchment paper.
Place lentils in a small to medium saucepan and cover with 2 cups of water; add ½ teaspoon salt. Bring to a boil over medium heat. Once boiling, reduce heat to low to keep simmering and cover loosely. Cook lentils for around 20 minutes, until lentils are soft but not falling apart. If they are not done at this point, check every 5 minutes until done. Strain if needed and let cool. Lay them on a baking sheet and pat dry with a clean lint-free towel.
Pulse rolled oats for several seconds in food processor, until small pieces are visible. Place in large bowl.
Pulse walnuts for several seconds to chop them. Place in large bowl.
Pulse garlic several times to mince. Add yellow onion and pulse for several seconds until roughly chopped. Add celery and repeat until chopped, being careful not to chop too fine. Place the mixture in a medium-large bowl.
Pulse the cooled lentils for a few seconds and place in the large bowl.
Add shredded carrot to the large bowl (or shred in food processor if not shredded yet). Add drained kosher dill relish, flaxseed meal, olive oil, parsley, coconut aminos, vegan Worcestershire sauce, poultry seasoning, 1 teaspoon sea salt, oregano, salt, black pepper, and cooked green lentils in the bowl. Mix together, then stir in the bread crumbs and psyllium husk powder, if using.
Place the mixture in the loaf pan, pressing it firmly with the spatula. Smooth ketchup on top in an even layer with a spoon.
Bake for 60 minutes until browning at edges. Let cool for 20 to 30 minutes, lift the meatloaf out of the loaf pan. Garnish with fresh thyme if desired. Slice and enjoy!
Notes
Serve with mashed potatoes and mushroom gravy, roasted green beans, roasted brussels sprouts, and cranberry sauce on the side.
Refrigerate for up to 4 or 5 days. Freeze for up to 1 month. Cut into slices, wrap and freeze. Pull out the individual portions as you need them and Heat until warmed through, approximately 40 minutes at 350°F.
Bake the meatloaf in a muffin tin for smaller portions; you will need to reduce the baking time to 20 or 25 minutes
Make this a day ahead to let the flavors blend. It's easier to serve the meatloaf once it has cooled completely.