Cook Rice: If you don't have cooked brown rice on hand, make that first as you'll need up to 45 minutes. I would recommend cooking the recipe the day before and storing in the fridge overnight for best results.
Prepare for Baking: When you're ready to proceed, preheat the oven to 350 F and line a standard-sized loaf tin with parchment paper so it sticks out over the sides. This will help you easily remove the nut loaf once cooked.
Mix Flax Egg: Mix the ground flax with the water in a small bowl and set side for 5-10 minutes.
Cook Vegetables: Heat the oil or butter in a large skillet or dutch oven on the stovetop over medium heat. Add the mushroom, garlic, onion, celery, salt and pepper. Saute the veggies for about 4-5 minutes, stirring often.
Add Seasonings: Add all of the herbs and spices, stir well, and cook for another 2-3 minutes. Stir in the tamari or soy sauce and tomato paste. Turn off the heat.
Process Nuts and Oats: While the veggies are cooking, add the oats, pecans and walnuts to a food processor and process into a grainy consistency. You don't want them totally pulverized but they should be fairly broken down. A few larger pieces left behind are ok.
Add Rice and Flax Egg: Add the cooked rice and flax egg to the food processor and pulse a few times to combine. Don't completely pulverize it, we want some texture in the final loaf.
Combine Mixture: Dump the contents of the food processor into the pot with the cooked veggies and stir well until it's thoroughly combined. If you don't have a large enough pot, transfer everything to a large mixing bowl to mix.
Press Loaf into Pan: Firmly press the nut mixture into the prepared loaf tin, using your hands or the back of a wooden spoon to press and flatten.
Mix Glaze and Add to Loaf: Either prepare the cranberry sauce or mix the tomato glaze ingredients together in a dish. Spread either the cranberry sauce or tomato glaze evenly over the loaf.
Bake: Bake for 60 minutes. Remove from the oven and let sit in the pan for 10 minutes. Use the edges of the parchment paper to lift the loaf out of the tin and onto a cooling rack.
Cool: Let cool for an at least another 30 minutes before carefully slicing. The long it sits the firmer it will be and better it will hold together. Don't worry, it will still be hot when you slice it open! If you're not slicing it right away you can let it cool completely in the pan then reheat in the oven later. Enjoy right away or see notes for storing.