Preheat oven to 400° F. In a large skillet, heat the oil for the enchiladas over medium-high heat. Sauté the jalapeño and bell peppers until they begin to soften, 3 or 4 minutes. Add the portabellas to the pan and cook for another couple minutes, until they darken in color.
Stir in the spices and transfer to a large bowl. Mix in half the shredded cheese and the cup of sour cream.
Rinse out the skillet and add the oil for the sauce. Cook the onions over medium-high heat while stirring until they soften, about 3 - 4 minutes. Sprinkle in the flour and cook while stirring for another minute, being careful not to let it burn.
Pour in the broth, tomato sauce, and spices, and let it come to a boil. Reduce to a simmer and cook until the sauce slightly thickens while you roll up the enchiladas.
Warm the tortillas and one-by-one roll up the filling inside. Place into rows with the seam side down in a large baking dish.
Completely cover the top of the enchiladas with the sauce, sprinkle with the remaining cheese, and bake until golden brown on top, about 18 to 20 minutes. Serve warm with sour cream and cilantro.