In a large bowl, mix the cooked brown rice and cooked lentils.To reduce your prep time, you could cook the rice and lentils the day before or use leftovers from a previous meal.
Add the quick oats, ground nuts, and poultry seasoning. Mix well and set aside.
Chop the mushrooms and celery in bite size pieces. Saute' in the vegetable broth until tender.
Add the remaining ingredients.
Mix well and turn off the heat.
Mix the sauteed vegetables with the lentil/rice mixture.
Add a can of tomato paste and mix well.
Spoon mixture into a parchment-lined loaf pan.
Cover pan with a piece of aluminum foil. Bake in a preheated 350 degree oven for about 40 minutes.
Remove foil and cook for an additional 15-20 minutes. It is done when the top is browned and edges look a little crispy.
Remove from the oven and cool for 10-15 minutes. The longer you allow the loaf to set, the firmer it's texture will be. Cooking this a day ahead is the best way to have a firm loaf. Just warm it up in your oven or microwave the following day.