Excellent idea for an exercise. Be interesting to see how you get one.
I guess the main question is what is your typical days diet ( or week ) looking like now?
It’s fairly flexible to be honest. This week has been mostly vegetarian (unintentionally, just happened that way) with lots of tomato, bread, aubergine, pasta, some eggs, mozzarella, olives, good quality olive oil.
Often it’s pretty high protein with a lot of beef and chicken, lamb probably at least once a month. That said, I’d actually like to reduce my meat intake and balance it so that I am eating the best meat I can get (quality and ethics wise), but less of it each day.
I eat a lot of broccoli, cabbage, asparagus, cauliflower, onions, swede, parsnips, tomato, peppers in all sorts of forms.
From food eaten this week, I think the olive oil, olives, tinned tomato and mozzarella would be an issue. Could replace those with British alternatives easily enough, though I’d miss the good quality extra virgin olive oil.
I might try a week of it to start with and go from there, perhaps a summer week and then a winter week later in the year.