Place tomatillos on a large baking sheet; bake at 500° for 7 minutes.
Place 1 tortilla on a baking sheet; bake at 300° for 3 to 4 minutes or until crisp. Break into pieces.
Place tomatillos, tortilla pieces, 1 cup water, 1/2 cup broth, and next 4 ingredients in container of an electric blender; cover and process until smooth, stopping once to scrape down sides. Transfer mixture to a saucepan; cook over low heat until thoroughly heated. Remove from heat; set aside, and keep warm.
Coat a large nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot. Add onion and garlic; saute until tender. Add remaining 2 tablespoons vegetable broth and beans; cook 3 to 4 minutes or until thoroughly heated. Remove from heat, and mash beans; stir in brown rice and cheeses.
Dip 1 tortilla in tomatillo mixture; spoon 1/3 cup rice mixture down center of tortilla, and roll up. Place, seam side down, in a 13- x 9- x 2-inch baking dish coated with cooking spray. Repeat procedure with remaining 11 tortillas, tomatillo mixture, and rice mixture. Spoon remaining tomatillo mixture over tortillas. Bake, uncovered, at 350° for 30 minutes.