Combine wild rice, brown rice, and beef broth in a 3-quart sauce pan. Bring to a boil and reduce heat to Low. Cover and simmer 50-55 minutes until rice is tender.
Meanwhile, slice mushrooms. Chop shallot. Chop (or crush) garlic.
Melt butter in a large skillet over Medium heat. Saute shallots 3 minutes. Stir in garlic; add mushrooms, salt and pepper. Saute 4 minutes or until mushrooms are dark and tender.
When rice is finished cooking, toss mushroom mixture with rice and serve while hot.
Special note: The recipe originally says to drain the rice. I've never had any extra liquid to drain, but I use a different rice as well. To make the recipe easier for me I bought a rice mixture at my store called "Royal Blend". I highly recommend it since it contains Texmati white, brown, wild, and red rice. This might be the reason no draining is necessary. If you are able to find this rice and buy it, use 1 1/2 cups of it instead of the 3/4 cup of both rice.