Add the tomatoes, salt, spices and the juice from the lime; simmer for a few minutes.
Add the chips and toss with the sauce until they start to soften a little bit.
Pour into the prepared baking dish and cover with the beans.
Bake for 10 minutes.
Remove from the oven; beat the eggs with the milk and gently pour over the beans without disturbing them. Return to the oven and bake for an additional 35-40 minutes, until a knife inserted in the middle comes out clean.
Add small dollops of sour cream on top and place under a broiler until the eggs and sour cream start to brown around the edges.