Shopping list creator

Hi, I'm new to this site, as I have a problem I'm hoping somebody can help with. I'll try and describe in as much detail as possible:

I have created an excel sheet for recipes that my wife and I cook regularly, just the ingredients. I have half achieved my aim to make this produce a shopping list for meals we choose for the week. I say half achieved as each item is listed separately even if there are multiple identical items. For example, the shopping list may call for 2 chicken breasts for Mondays meal, and 2 chicken breasts for Thursdays meal, but what I really want is for it to create a more streamlined list which would just have 4 chicken breasts.

I realise that this is an unsual request, but if anybody can help me out I'd appreciate it. If it would be useful to attach my work in progress, I will do.

Many Thanks,

Dom