Can you define what nose to tail means?

I started off doing this elimination diet www.liondiet.com but after 10 days my heartburn and swelling in my knees went away so I assume I wasn’t severe and didn’t need to “cleanse” for around 3 months like they said you should do it up to on their website. So on the 10th day I reintroduced eggs and just yesterday on the 16th day I reintroduced fish by having some wild smoked mackerel which was extremely satiating and yummy since it’s very oily and fatty😋lots of omega 3 and such. So at the moment my diet consists of ruminant meat(beef, lamb etc), eggs, and oily fish such as sardines, mackerel and salmon(wild caught only) I love shellfish though like prawns and stuff so if I find some wild caught I will have some here and there too, but unfortunately in the UK where I currently live almost everything is farmed so I have to avoid!!