I work in a wedding venue and am married to a Head Chef.
I absolutely am not condoning what has happened. However, here are some possible reasons- which I hope you can use constructively to sort this out.
- Cost of ingredients- they've realised that if it was priced a long time ago, they won't make anything. For those saying fish and chips is straightforward- a bag of potatoes (that are suitable for chips) have now gone from around £8 a sack last year to around £12. Not all spuds make decent catering chips. If they are working on small margins, this could mean a loss. Fish is up by about 40%. (Depending on the fish) Oil is almost double and we all know the price of electric!
- Staff. They may be a) short staffed or b) don't have skilled staff. You mention the starter was unusual- it is possible that they don't have enough skilled staff to do it. (Skilled is the operative word.) The shortage of skilled chefs is truly chronic. Or, it may be that there aren't just enough physical people to get the meals out in a timely fashion. Large scale catering is actually difficult if not well organised. There are time when you just need 'hands' to put things on the plate.
(As an aside, a company offered my Husbands Sous Chef a £1000 bonus if he walked out there and then and started work with them. He didn't)
3.There has been a genuine mess up and the Head Chef has given you a menu which isn't actually in your price range. This can happen if couples want to write their own and the HC isn't very good at costings. (People would be surprised at how much time a chef spends behind a spreadsheet.) It could be that he's ok with the margins and his bosses aren't.
Just as an aside, do you have guests with a lot of dietaries? I'm sure people will want to shout at me on here, but catering for dietary requirements costs lots of money. Gluten free catering flour is now £5 a bag. (And before anyone tells me how much it is in the supermarket, domestic products don't always work in a commercial kitchen and commercial ovens) Vegan Cream that doesn't split in a oven is double the price of dairy cream. It also 'costs' a lot of time- and again, if they are very short staffed, this may be an issue. We cater for all sorts of allergies and it can be time consuming. If they haven't taken this into account, it's going to cost them. I'm not saying it's right, I'm just trying to give you enough knowledge to help you.
Saying that, the offer of champagne is....awful.
I would suggest you ask them for transparency. If they are short staffed, there isn't much they can do about that and you and the company need to come up with a menu that a) you like and b) the kitchen can actually produce.
If it is the cost, again, they need to work with you- perhaps the starter can be made more cost efficient; could a sauce or garnish be removed, or could it be prepped in a easier way? Or could the fish be changed for a more cost effective fish? Could the meat be a cheaper cut? Could a dessert be simplified?
I don't want to be the voice of doom but so many places have gone under recently. Many hotels in our area didn't make it through the pandemic, so we have had a big surge in wedding bookings as there is nowhere else to go. It's possible that your venue is just holding on at the moment.
The communication you have received is terrible. I would suggest that they need to work with you to come up with a menu that works for both sides and them just imposing it on you it rubbish. Asking for additional money at this stage, without a full and proper explanation is really bad practice.
I wish you all the best- drop me a message if you need any more info!