Add water to a large pot and bring to a boil over high heat. Once boiling, add rice and cook for 30 minutes. Then drain for 30 seconds, return to pot off of heat, and cover for 10 minutes*. Set aside.
In the meantime, preheat oven to high broil and place a rack at the top of your oven.
Lightly brush whole poblano peppers with oil. Place on a baking sheet and broil on high for 1-2 minutes on each side, or until lightly blistered (see photo).
Turn oven off broil and preheat to 375 degrees F (190 C).
Let peppers cool for a few minutes. Then peel away any blistered skin and use a paring knife to cut out the stem. Also cut a slit down one side of the pepper and use your hands or a spoon to scrape out the seeds. Set aside.
Heat a large metal or cast iron skillet over medium heat. Once hot, add oil and onion and sauté for 4-5 minutes, or until soft and translucent.
Next add cooked rice, cumin, sea salt, salsa and cilantro. Stir to combine. Taste and adjust seasonings as needed.
In a separate small saucepan over medium heat, add pinto beans and season with cumin and sea salt to taste. Once bubbly and hot, remove from heat and set aside.
Place peppers in a lightly greased, large baking dish (9x13-inch is best as original recipe is written // adjust if altering batch size) and scoop generous amounts of the rice filling into each pepper using a spoon. Top with beans and a bit more salsa and cover the dish with foil.
Bake peppers at 375 degrees F (190 C) for 15 minutes. Then remove foil and bake for another 10-15 minutes uncovered. The longer they bake, the more tender the peppers will become.
Let cool slightly before serving with desired toppings (see options above). Best when fresh, though leftovers keep in the refrigerator for 2-3 days. Reheat in the microwave or in a 350-degree F (174 C) oven until warmed through.
*Rice cooking method from Saveur. *Nutrition information is a rough estimate calculated without additional toppings.