Add the remaining 2 teaspoons oil to the pan and heat until very hot. Add garlic, ginger, chiles and the reserved orange zest; stir-fry until fragrant, about 30 seconds. Add broccoli and water. Cover and steam, stirring occasionally, until the water has evaporated and the broccoli sizzles, about 3 minutes. Add bell pepper and stir-fry for 1 minute more.