Puree all but 3 tablespoons cilantro with 2 cups water, the garlic, chile powder and 3/4 teaspoon salt in a blender until smooth. Transfer to a medium saucepan along with the rice and bring to a boil. Reduce the heat to low; cover and cook until the liquid is absorbed, about 18 minutes. Uncover, stir and let cool 5 minutes.
Meanwhile, bring the black bean soup to a simmer in a small saucepan over medium-high heat and cook until the liquid is slightly reduced, about 3 minutes. Stir in the spinach and return to a simmer. Remove from the heat and cover to keep warm.
Toss the corn, tomato, lime juice, the reserved 3 tablespoons cilantro, 1/2 teaspoon salt, and chile powder to taste in a large bowl.
Warm the tortillas in a dry skillet or in the microwave. Divide the rice, bean mixture and cheese among the tortillas; top with some of the corn salsa. Fold up the bottoms of the tortillas, then fold in the sides and roll up. Serve with the remaining corn salsa.
Photograph by Justin Walker
Recipe courtesy of Food Network Magazine