Saute onions in butter or olive oil on medium-low heat until translucent (about 5-6 minutes).
Add mushrooms, saute until mushrooms soften a bit (about 3-4 minutes). Mix in turmeric and cumin. Saute a few more minutes until mushrooms look totally soft.
Pour farfel into a large bowl. Toss in mushroom mixture with farfel. Add salt, fresh oregano and enough broth to moisten farfel, but not enough to make too soggy.
Put entire mixture into a loaf pan . Bake for about 15 minutes in oven, turn heat to broil, then set under broiler for about 1-2 minutes to let top brown a bit (but watch carefully so you don't burn to top).