1876, American English, from Mexican Spanish enchilada, fem. past participle of enchilar "season with chili," from en- "in" + chile "chili" (see chili).
You never ate enchilada, did you? I hope you never will. An enchilada looks not unlike an ordinary flannel cake rolled on itself and covered with molasses. The ingredients which go to make it up are pepper, lye, hominy, pepper, onions chopped fine, pepper, grated cheese, and pepper. ["The Health Reformer," December 1876]