Hi Heather,
Aji is the South American term for chile and I believe it also refers to pod type. If a recipe just calls for an aji chile then jalapeno would be a good substitute or if a specific aji chile is named select a pepper that is fairly equal on the heat scale (anyone with more experience please feel free to correct me). Here are some descriptions of chiles with Aji in the name (source: Hormel):
Aji Amarillo Chile
A variety of chile pepper that is native to the Andes region of Chile. Hot in flavor, it is yellow in color and provides a distinctive citrus aroma.
Aji Limon Chile
A Peruvian chile that is 1 to 2 inches in length and grows upright or horizontally, instead of downward or as a hanging fruit. Green in color when it is immature, this chile becomes bright yellow and hot in taste as it matures. The aji limon has a mild lemon or fruity flavor and is an easy chile to grow in pots or small spaces. It is also known as a Peru yellow aji.
Aji Panca Chile
One of the most common chile peppers in Peru, this chile is considered to be one of the larger types of chilies grown. Growing from 3 to 5 inches in length, the aji panca has a somewhat thick flesh that matures from a green to dark red in color. This chile is mild in heat intensity and provides a fruity, berry-like flavor that goes well in stews, sauces and fish dishes.
Aji Serranito Chile
A variety of chile, common in Peru, that grows downward to a length of 2 to 3 inches. As an immature chile it is green in color and becomes red as it matures. It is a cross between an aji amarillo and a serrano chile, providing a mildly hot tasting chile.
You'll find more information and photos here:
The Chile Pepper Institute at New Mexico State University (click here)Chile Chart - Click on Chile Names for Photos and descriptions (Cross County Nurseries) (click here)Happy Cooking!
Betsy
In reply to:
My mouth has been watering ever since I read Brad's description of this stuff. My family always jokes that we are the only ones we know who would go on long and dangerous journeys for our food...but ah, we have met a kindred spirit! With that being said...could somebody please tell me what Aji chilies are? I have never heard of them. Are their other names for these chilies? And is the best substitute the jalapeno? Thanks!
Heather Wisconsin