1. Heat oil in a large saute pan over medium-high heat. Add onions and cook, stirring frequently, for 5 minutes. Reduce heat to medium and cook, stirring occasionally, until beginning to caramelize, about 13 minutes.

2. Add garlic and cook until soft, about 2 minutes. Add green beans, chiles, water, salt, and pepper, and bring to a boil. Cover, reduce heat, and simmer until green beans and chiles are tender and liquid has evaporated, 20 to 25 minutes. Serve immediately.