large jalapeños, sliced into 1/4-inch rings and seeded
salt and freshly ground black pepper
Preheat the oven to 450°. Place a rimmed nonstick baking sheet in the oven to preheat. In a bowl, toss the potatoes with the oil and jalapeños and season with salt and pepper. Transfer the potatoes to the baking sheet, turning them cut side down. Roast on the upper rack for about 35 minutes, until the potatoes are tender and golden, and serve.