Purpose/Objectives: Chef's Adopt a School (CAAS) is an evidence-based food education program delivered in schools (Kindergarten-12th grade) in the United Kingdom (UK) which helps children understand the importance of nutritional literacy and encourages healthy eating. This qualitative study investigated the underlying components of the CAAS program that contributed to improving children's healthy eating attitudes and behaviors. This study addresses the gap in the literature of process evaluations of food education programs. Methods: An exploratory case study design was implemented using the first unit of the CAAS program; the Taste and Sensory lesson (session one). This lesson involved two separate classes of children (mean age of 8.5 years) from two London elementary schools (N = 54; 30 boys and 24 girls). Data were collected using a variety of qualitative methods: Observations of the session in each school, one focus group per school with a subgroup of students, and semi-structured interviews with chefs (delivery agents) and class teachers. Data sets were collated and thematically analysed manually, generating three thematic categories and eight subthemes. Results: Main themes comprised: 'Social Validity' which encompassed stakeholders' perceptions of the program as both worthwhile (effective and valuable) and acceptable (engaging); 'Pedagogies and Practices' which included specific teaching and learning techniques underpinning the program; and 'Championing Healthy Eating' which captured emergent factors related to program development and diffusion. Applications to Child Nutrition Professionals: Pertinent issues for developers and implementers of other food education programs to consider were identified with this research. Specific components of CAAS (e.g. making learning 'fun' and the emphasis on experiential learning) were linked to program effectiveness and align with findings from similar studies in the literature. The importance of implementing good practice in program evaluation and development (e.g. assessing intervention fidelity and incorporating children's 'voice') was highlighted in this research and is universally applicable.