-
1
Pre-heat oven to 300F (150C), 150 degrees C, gas mark 2.
-
2
Bake the tortillas directly on the oven shelf for 15 to 20 minutes, turning once until crisp right through.
-
3
They will break with a clean snap.
-
4
Break into coarse pieces and set aside.
-
5
Spread onion pieces out in a heavy frying pan.
-
6
Cook over moderate heat without stirring until the onions are sizzling and beginning to stick to the pan.
-
7
Stir in the stock and let it bubble up, stirring up the browned deposits in the pan as it bubbles.
-
8
Stir in the garlic and the spices.
-
9
Turn the heat down and simmer, stirring frequently until the mixture is thick, not at all soupy, and the onions and spices are frying in their own juices.
-
10
Don't rush this step.
-
11
It is essential that the spices should not have a harsh raw taste.
-
12
Stir in the black beans and heat gently.
-
13
Mash roughly while still in the pan, with a potato masher.
-
14
You want a rough lumpy mixture, not a smooth puree.
-
15
Set aside.
-
16
In a gratin dish spread a layer of a third of the tortilla pieces.
-
17
Spread a layer of the black beans over the tortillas and spread a third of the tomato sauce over the black beans.
-
18
Sprinkle with one third of the cheeses.
-
19
Repeat this, ending with a layer of the beans, sauce and cheeses.
-
20
Bake for 30 minutes covered.
-
21
Uncover, and bake for 5 to 10 minutes more.
