The company 'L'antre-temps' has several core activities: 1. **Accompaniment and Coaching**: Christa Müller offers accompaniment and coaching to help people find their life path and unfold their potential for health and well-being. 2. **Agriculture and Alpine Farming**: The company operates an alpine farm in Kaltenbrunnen and offers experiences and activities in the field of agriculture and alpine farming. 3. **Cheese Production**: L'antre-temps produces cheese and offers cheese-making courses. 4. **Gastronomy**: The company offers culinary experiences and events, such as fondue evenings with homemade cheese. Overall, the core activity of the company can be described as 'Accompaniment, Agriculture, Cheese Production and Gastronomy'.