Teaching in interdisciplinary fields such as Renewable Energy Engineering faces various challenges, including conceptual complexity and the heterogeneity of students’ academic backgrounds. This study aimed to propose and evaluate a novel instructional method called P.N.P. (Persian acronym for “Simple Question, Key Point, Humorous Answer”). The P.N.P. approach is based on posing simple, seemingly obvious questions accompanied by humorous answers across three levels of difficulty, with the goals of stimulating curiosity, reducing anxiety, and promoting active classroom interaction. The research employed a quasi-experimental one-group pre-test–post-test design, and the study population consisted of Renewable Energy Engineering students at Shahid Beheshti University. Data were collected using a written test and a multi-construct questionnaire assessing retention, cognition, psychological aspects, interaction, and limitations. Results from implementing this method over seven academic years indicated that P.N.P. led to a statistically significant increase in students’ test scores. Moreover, questionnaire analyses conducted in SPSS 27 showed concurrent improvements in concept retention, cognition, psychological indicators, and instructional interaction. Accordingly, P.N.P.—which integrates humor, multi-level content structuring, and active participation—can be regarded as an indigenous and creative model for enhancing teaching quality in specialized and complex domains.