Heat oil in a small saucepan over medium-high heat.Add flour and stir together over the heat for one minute.Stir in the remaining seasonings (chili powder through oregano).Then gradually add in the stock, whisking constantly to remove lumps.Reduce heat and simmer 10-15 minutes until thick.Use immediately or refrigerate in an air-tight container for up to two weeks.Preheat the oven to 180º C.Cut the tortillas into eighths and place on a baking sheet.Spread on two baking sheets. Bake until crisp, 10-15 minutes.Meanwhile, heat the oil in a wide skillet set over a medium flame.Add the onion and garlic and cook, stirring until tender, a couple of minutes. Add the black beans, mix well and cook for a couple of minutes.Place the tortilla chips in a large bowl, pour in the enchilada sauce, and toss with your hands to coat.Oil a large baking dish and place the tortilla pieces in a single layer.Top with the black beans. Sprinkle on the cheese.Use the back of a soup spoon to make 4 hollows in the chips. Carefully crack the eggs into the hollows and sprinkle with a few pinches of salt.Place in the oven and bake until the eggs are set to your liking, 10-15 minutes.Remove from the oven, scatter the chevre and cilantro over the top, and serve immediately with the salsa, sour cream and more enchilada sauce for drizzling over the tops.