I love the complex flavors of oils and butters infused with herbs, peppers, and, in my world, always some kind of Peruvian pepper. Depending on how you store them, they can keep for weeks or even months.
Infusing oil with spicy rocoto peppers tames their heat just enough, and the garlic, tomato paste, and other seasonings add complexity. I drizzle this oil on shrimp dumplings (page 59), but it would be good on top of most fish. Or, just use it like your favorite hot sauce.
To make Rocoto Oil: Heat ¼ cup olive oil in a small saucepan over medium heat for a solid minute, then add 2 tablespoons finely minced red onions and cook until the onions are translucent, about 2 minutes. Stir in 1 tablespoon rocoto paste (page 34), 1 tablespoon tomato paste, and ½ teaspoon garlic paste (page 37) or 1 minced garlic clove. Simmer for about 1 minute, add 1 bay leaf and ⅓ cup water, stir, and raise the heat to medium-high. Boil until the water has almost evaporated, about 5 minutes. Remove the pan from the heat and pour in another ½ cup olive oil and 1 teaspoon sesame oil. Transfer the oil to a small bowl, cover, and refrigerate for 24 hours. Strain the oil through a cheesecloth-lined strainer (preferable) or at least twice through a fine-mesh strainer. Do not push down on the solids. Cover and refrigerate the rocoto oil for 2 to 3 weeks. Makes a generous ½ cup.
Everything from Conchas a la Parmesana (Parmesan-baked scallops, page 53) to the simplest steamed or grilled summer corncobs or baked potatoes loves this mildly spiced butter.
To make Ají Amarillo Butter: Place 8 ounces (1 cup) room temperature unsalted butter in the bowl of a stand mixer fitted with the paddle attachment and mix on medium-low speed until fluffy, about 2 minutes. Add 2 tablespoons ají amarillo paste (page 34) and whip for 2 minutes more, or until the pepper paste is fully incorporated into the butter. Wrap the butter in plastic wrap and refrigerate for up to 1 week, or freeze the butter in a flat, thin layer in a medium plastic food storage bag so you can break off small pieces as needed. Makes 1 cup.