1. For the enchilada sauce,place a medium frypan over medium heat. Add the oil and flour and whisk until combined,almost as if you are making the base for a bechamel sauce. Add the remaining sauce ingredients,reduce heat to low and simmer for 25 minutes,stirring occasionally to prevent catching. Once it has thickened and starts to smell glorious,remove from heat.
2. In a mixing bowl,place the shredded chicken,black beans and finely chopped red onion,then add enough enchilada sauce to just coat. Reserve remaining sauce for assembly.
3. Preheat oven to 175C.
4. To assemble,lay your tortillas on a flat work surface,and scoop out chicken mixture into the centre of each tortilla. Be careful not to overfill,you want to be able to enclose each enchilada comfortably.
5 Depending on what size flour tortillas you find,try to use a large baking dish that fits them lengthways,so you don't have to cut or jam your filled enchiladas into the dish (20-25cm tortillas work best). Snugly fit as many filled,wrapped tortillas as you can into the dish,placing them seam-side-down. Cover the enchiladas with the remaining sauce.
6. Top with the cheese and bake in the oven for 20 minutes or until warmed through and the cheese is bubbling and golden on top. Season with salt and pepper and scatter over basil leaves,if using. Serve piping hot.
*Note:you can freeze the sauce separately or freeze the baked enchiladas;simply thaw then reheat in the oven.
If you like this recipe,try my tomato'quarantine sauce' (plus 10 ways to use it)