Chop all the fresh produce. Make sure to remove the seeds from the poblano peppers before dicing. You can chop the entire bunch of cilantro, including the stems. (Be sure to chop it finely.)
Set a medium saucepot over medium heat. Add the butter, diced poblano peppers, onion, cilantro, and garlic. Sauté for 5 to 8 minutes, until the onions and peppers are soft.
Stir in the ground cumin, salt, and rice. Stir well so that all the grains of rice are coated with butter and seasoning.
Pour in the vegetable broth. Stir, then cover the pot with a tightly fitting lid and simmer for 15-17 minutes. Do not stir again, and do not repeatedly lift the lid.
The rice is done when it looks dry and fluffy on top and there are vent holes covering the surface of the rice.
Remove the pot from heat, keep it covered, and let it steam another 5 minutes. Then fluff and serve warm.
Notes
Pro Tip: My favorite pot for cooking rice has a glass lid. This makes it easy to check for vent holes in the top of the rice, without lifting the lid.Leftover green rice tastes great the next day, and is great to enjoy for lunch. Let Arroz Verde cool completely before transferring it to an airtight container. Keep in the refrigerator for up to 4 days.To reheat, sprinkle a bit of water over the rice and microwave in 20-second increments. Stir between each burst, and add more water as needed to help the rice fluff up again. Alternatively, leftovers can be reheated in the oven. Again, sprinkle with water, and then place the rice (in an oven-safe dish, of course) in a 350°F preheated oven. Cook for 5 minutes, stir, and cook for another 5-10 minutes until warmed throughout.