2. Step
Heat oil in a medium ovenproof skillet over medium-high heat until shimmering. Add onion, bell pepper, poblano and jalapeño; cook, stirring occasionally, until softened, 7 to 9 minutes. Add garlic and cumin; cook, stirring constantly, until fragrant, about 1 minute. Sprinkle flour over the vegetables and cook, stirring constantly, until they are thoroughly coated, about 1 minute.