Preheat oven to 425 degrees F.
Whisk flour and 1/2 cup broth in a small bowl. Combine the remaining 1/2 cup broth, salsa and cumin in a medium saucepan. Bring to a boil and whisk in the flour mixture. Cook over medium heat, stirring occasionally, until reduced to about 2 1/2 cups, 6 to 8 minutes. Stir in 1/4 cup cilantro.
Spread 1/2 cup of the salsa mixture in a 9-by-13-inch ovenproof baking dish. Combine chicken, beans, cream cheese and 1/2 cup of the salsa mixture in a large bowl. Spoon 1/4 cup of the chicken mixture onto the center of each tortilla and roll it up into a cigar shape. Arrange, seam-side down, in a single layer over the salsa mixture in the baking dish. Top the enchiladas with the remaining salsa mixture.
Bake until bubbling, about 15 minutes.
Remove from oven; increase oven temperature to broil. Sprinkle the enchiladas with cheese. Broil 8 inches from the heat source until the cheese is melted, 2 to 3 minutes. Top with tomato and the remaining 1/4 cup cilantro and serve with sour cream.