Start by de-husking the tomatillos. Give both the tomatillos and tomatoes a good rinse. I usually cut out the stems knowing that any juices leftover in the roasting pan will go into the blender.
Roast the tomatoes and tomatillos in the oven (400F) for 20 minutes or until you need them.
Prep the other ingredients and give the cilantro a good rinse. I usually twist off and discard the bottom, thicker portion of the stems, but use the upper stems that hold the leaves together.
Add a glug of oil to a saucepan along with 1 cup white rice. Saute over medium heat until the rice is turning golden brown, stirring regularly.
Add the roasted tomatoes and tomatillos to the blender along with the 1/2 onion, 1/2 jalapeno, 1 peeled garlic clove, and half of the cilantro (optional). Combine and take a taste, adding more jalapeno if you want more heat. Note: I usually add half of the cilantro to the blender and chop up the other half to add to the cooked rice.
Add the blender mixture to the rice (once it's turning golden brown) and cook for a minute or so. Add 1 cup stock and 1/2 teaspoon salt. Bring to a boil and then reduce heat to a simmer. Cover and let cook until all the water is absorbed.
Once cooked give it a good stir and take a taste for seasoning, adding more salt if necessary. Cover and let sit in its own steam for a few minutes before serving. You can optionally add the other half of the cilantro (finely chopped) to the rice before serving.
Serve immediately. Store leftovers in an airtight container in the fridge.