When I had a roast beef disaster I made Nigella's Slow cooker pasta replacing the lamb with shredded/chopped beef
The sauce made the meat very moist
http://www.nigella.com/recipes/view/slow-cooker-lamb-and-pasta
Congratulations on your engagement
Sadly I don’t think you are going to find all of your wishes
-a beautiful country/manor house
-grounds with gardens and a preferably a lake
-tables for a lunch or dinner
-all within your budget around £20 a head and no more than £50
I think what you and your fiancé need to do is to sit down and decide how to prioritize your spending on what elements of the day are most important to you:
-is it necessary to invite 100 people? – this is a big cost. Many people do not invite children to weddings (although this can be cultural). Or could you have a meal with the wedding party only and then an evening reception/party at someone’s home or a hall.
-If the venue is most important to you would you be prepared to compromise on food and just serve canapés (like Will and Kate) or afternoon tea? Remember that the priced menus are just the start and often there are service, drinks and cake charges on top.
-are you flexible on dates? Midweek in November/February could be cheaper than peak summer Friday-Sunday weddings for a smaller hotel. Some smaller village hotels and country Inns might offer a good price if you keep things very simple
-many people have mentioned church and community halls – if you find one in a pretty village many have gardens (although they may lack the grandeur of a country house). You could get caterers to provide food and buy your own drinks – or perhaps you have relatives that could help out making food. My cousin did her wedding as a pot-luck supper in a village hall. The downside is that saving the money on paid staff means you have to organize your own set-up, clean up and wash-up.
-or have a smaller wedding here in Dubai and then a party in the UK
- could you rent a country cottage or use someone's home?
Good luck with your wedding planning