The tasty ones. For cheese, could be anything from a properly ancient cheddar for nibbling, plasticy red leicester for quick cheese on toast, camembert for lunch while cycling in France, a collection of the seriously nice cheeses the local posh cheese shop does for post dinner cheese and port etc. Peanut butter I'm less particular about and don't eat much of, but I think we get a decent organic crunchy one these days - no sugar, I prefer the slightly rough taste.
Now, with the toast in the cheese on toast, the biscuits or crackers with the cheese and crackers, the baguette with the french lunch, etc, I'll need to consider insulin for all of these - lunch while cycling will need less, port will add extra complication of sending BG up from the immediate sugar, down for the alcohol. The fat in the cheese and peanut butter may slow down carbohydrate absorbtion a bit too - probably depends a lot on the type of cheese, so this is something experience will help with.
Cheese and peanut butter are both high energy foods, so best eaten in moderation for anybody - T1D or not. But that applies to all food - binge eating a 200g bar of dairy milk vs a block of cheese vs a jar of PB aren't great things to do
The NE in DAFNE stands for Normal Eating. Count the carbs, inject the insulin, enjoy the food
(annoyingly my mouth has started watering at the thought of all that cheese. I shall distract myself with some work...)