Mexican Green Rice

1/8 cup vegetable oil
1 cup Basmati or long-grain rice
2 large poblano chiles, tops removed,
    seeded, and diced
1 cup fresh cilantro leaves
3 garlic cloves, mashed
1/2 onion, diced
2 tablespoons chicken bouillon granules
Salt
Pepper
1 cup frozen peas and carrots
1 tablespoon butter

In a Dutch oven with a tight-fitting lid, heat oil and saut