Instant Pot Street Corn Queso

Set Instant Pot to Sauté and heat vegetable oil. Add corn and cook, stirring occasionally, until corn takes on some golden charred color, 4 to 6 minutes. Remove corn from Instant Pot and set aside in a bowl. Still on the Sauté function, add butter and let melt. Add garlic and cayenne and cook until fragrant, 1 minute. Add flour and whisk until smooth, then cook 1 to 2 minutes, until flour is no longer raw. Add milk and bring up to a simmer. Cook, stirring occasionally, until milk has thickened slightly, 2 to 3 minutes more. Add cheese and whisk until smooth and melted completely. Switch Instant Pot to "Keep Warm" and cover until ready to serve. When ready to serve, give queso a final stir and season with salt if needed. Top with charred corn, queso fresco, onion, jalapeño, and cilantro. If using, finish with a pinch of chili powder. Serve with chips.