Adjust an oven rack to the highest position and preheat the oven to 500˚F.
In a large pan over medium-high heat, warm the oil. Once the oil begins to shimmer, add the onion and chile, spread them out in an even layer in the pan, and cook until the onion becomes translucent and starts to lightly char, 5 to 7 minutes.
Increase the heat to high and add the tomatoes, using the back of a spoon to lightly crush them. Cook, stirring occasionally, until the tomatoes break down into a chunky sauce, 5 to 6 minutes, then add the salt.
Put the cooked rice in an 8-inch square (or similar size) baking dish, then fold in the tomato sauce. (You can also do the folding in a separate bowl and then transfer the rice to the baking dish, if you doubt your ability to not spill rice and sauce everywhere.) Evenly distribute the grated cheese over the top.
Switch the oven to broil and place the baking dish on the top oven rack. Broil for about 3 minutes, until the top bubbles and turns golden brown. Serve immediately. |