Preheat the oven to 450 degrees Fahrenheit/230 degrees Celsius.
Cut the tomatoes in half, then place them, cut side up, on a baking tray with a rim to catch any juices that overflow. I line the baking pan with aluminum foil for easy cleanup.
Sprinkle a teaspoon of the Mexican oregano followed by the salt and ground black pepper to taste. Drizzle on a tablespoon of olive oil.
Wrap the garlic cloves in a piece of aluminum foil and drizzle with a bit of olive oil. Ball up the foil and place in the baking tray with the tomatoes.
Place the baking tray in the oven and roast 25-30 minutes or until the tops have black spots and the tomatoes look really soft.
Let the tomatoes and garlic cool enough so you can handle, then place the tomatoes and peeled garlic in a blender. Process into a coarse puree--don't add any water.
Heat the remaining tablespoon of olive oil. Add the tomato puree and cook for a few minutes, stirring frequently, until most of the liquid has evaporated.
Add the Mexican oregano followed by the tomato paste. Mix well.
Stir in the rice. Cook for a couple of minutes until the rice grains look a little opaque. Stir in paprika and four cups water or vegetable stock. Mix well.
Let the rice cook, uncovered, over medium heat, stirring occasionally, until a good deal of the water has been absorbed but there is still some moisture left in the pot.
Give the rice one final stir. Check for salt and add more if needed at this time.
Lower the heat to the lowest setting on your stove, cover the rice with a tight lid, and let it cook, undisturbed, for 20 minutes. Don't peek.
Turn off the heat after 20 minutes and let the rice stand, undisturbed, for 10 more minutes.
Uncover, fluff up the rice grains with a fork, garnish with cilantro, and serve hot.