Ají amarillo, an orange-yellow chili with a fruity yet earthy flavor, is ubiquitous in Peruvian cuisine. The fresh chilies are difficult to find in the U.S., but ají amarillo paste, sold in jars, is available at well-stocked markets and specialty stores. The paste is key to the deep, spicy flavor of this quinoa chowder. If you can’t find it, use 1 or 2 minced jalapeños instead (if you like, seed the jalapeños for milder heat). The soup is especially good made with fresh in-season corn but, in a pinch, substitute frozen corn kernels. Serve with a simple salad of shredded cabbage, sliced avocado and crumbled queso fresco.
Don’t forget to rinse the quinoa to remove the naturally occurring saponin that gives quinoa a bitter flavor. But check the packaging first, as some quinoa is sold prewashed; if so, there’s no need to rinse.
In a large Dutch oven over medium, heat the oil until shimmering. Add the onion and cook, stirring, until light golden brown, about 4 minutes. Add the ají amarillo paste, oregano, 1 teaspoon salt and ½ teaspoon pepper. Cook, stirring constantly, until fragrant, about 30 seconds.
Stir in the sweet potato, corn, quinoa and broth. Bring to a boil, then cover and reduce to medium-low. Cook, stirring occasionally, until the potatoes and quinoa are tender, 16 to 19 minutes. Taste and season with salt and pepper. Off heat, stir in the cream. Ladle into bowls, sprinkle with mint and serve with lime wedges.