I once made a tagine from a radio broadcast in Gib which included 2 heads of garlic, it was inedible. When I asked the broadcaster about it, he owned a restaurant we used, he said that because Moroccan heads of garlic are tiny it needed a whole one, so when I explained that we'd sailed up into Spain at the weekend and brought back some huge garlic heads he saw the problem!
A friend made a rice mould, remember those(?), for a supper party. The recipe said to add Tabasco 'to taste', she added it until it was as pink as the picture. It was so hot and inedible. When she checked the recipe she saw the bit 'for a pink colour added a little food colouring'.