Final answer:
The intensive cooking workshop Rachel attended offered little instruction and was mostly a trial in fire.
Step-by-step explanation:
The phrase "a trial in fire" is an idiomatic expression that means a challenging or difficult experience that tests one's abilities or resilience. In the context of the sentence, it suggests that the intensive cooking workshop Rachel attended did not provide much guidance or instruction; instead, it was more of a hands-on, challenging experience where participants had to navigate and learn through practical experimentation and problem-solving. The use of "trial in fire" conveys a sense of intensity, difficulty, and perhaps unpredictability, highlighting the demanding nature of the cooking workshop and emphasizing the hands-on, experiential aspect of the learning process.