Preheat the oven to 375°F. Lightly oil an 8-inch square baking dish with olive oil and set aside.

Heat the olive oil in a large skillet or saute pan over medium-high heat. When hot, add the onion and pepper and cook, stirring frequently, for 7 to 10 minutes, until the onion is soft and translucent and just starting to brown around the edges. Stir in the chopped spinach, drained tomatoes and chiles, spices, and salt. Cook for another couple minutes, until the spinach is wilted and most of the liquid in the pan has evaporated. Transfer the vegetable mixture to a large bowl and add the bread cubes and one cup of shredded cheese. Set aside.

Place all the ingredients for the custard in a blender, and blend on high speed until smooth and creamy. Pour the custard over the bread, vegetable, and cheese mixture, and mix well with a spatula until everything is well-coated. Scoop into the prepared baking dish and press down firmly to level the top and eliminate air bubbles. (If you're making this in advance, you can do these steps up to 24 hours in advance, then refrigerate until you plan on baking the strata.) If not making in advance, allow to strata to sit for 10 to 15 minutes, so the bread can absorb the custard.

When ready to bake, sprinkle the strata evenly with the remaining 1/2 cup of cheese, then place on a baking sheet and carefully transfer to the oven. Bake for 45 to 50 minutes, or until the strata is firm and bubbling around the edges.

Remove from the oven and allow to cool for a few minutes, which will make slicing easier. Slice into portions and serve warm, topped with cilantro or green onions and hot sauce, to taste.