[Shellsfeathers&fur]

What else are you feeding your Horsfield? Chicory is not ideal and peppers shouldn't be fed. How do you know it is his favourite? Most probably the colour is attracting him?

Get him onto some weeds and flowers from the garden. Take a look at the Tortoise Table website. Is he outdoors?

Add some information as to his set up, lighting, heating, substrate etc and then we can give more help, plus photos.