Escabeche is a Spanish term which simply means pickled. Pickled vegetables such as carrots, onions, jalapeno peppers are some of the most common pickled condiments in Mexico. They are typically served as a side dish with other Mexican foods and they are a staple at most Mexican taquerias. The term is also used for other dishes that use a sauce made with vinegar, sugar, garlic, olive oil and chiles. Recipes for fish or chicken escabeche are common.
You can purchase jalapeno escabeche in cans or jars in Mexican markets. Picked vegetable are not difficult to make. Here is a recipe for Jalapenos en Escabeche which includes onions, carrots, jalapenos, white vinegar, pepper and olive oil.