This is traditional Peruvian spicy cheese sauce, often served over boiled and sliced potatoes. The recipe was created based on my experiences living in Peru and makes for a delicious and easy dinner starter. Serve at room temperature or cold over boiled potatoes and top with sliced boiled eggs and kalamata olives; dust with paprika (or rocoto if you have some).
Finding the aji can be difficult, but I've had luck just purchasing it online, through Amazon(R), for example. This is often an appetizer course.
You can also use 1/2 cup jarred aji paste in place of the raw peppers. Shredded mozzarella cheese can be used in place of queso fresco. Whole milk can be used in place of evaporated milk.