This is going to sound SO pretentious. But it is what I feel, so here goes. All our tates are different and I am NOT, NOT, NOT judging anyone who likes different foods. I'm just saying what I like. Each to their own.
I agree with some other Mumsnetters that purchased party foods are horrid. Bland, over-processed, salty, too much pastry (which I don't like) and often far too fatty. Mostly they don't taste of anything except hot fat and salt. And, as previous posters have also said, they are an indigestible mix of poorly-imitated different cusines.
I am a vegetarian and IMHO the OP's lasagne sounds nice. And it's real food, made with lots of lovely real vegetables. (I can't stand fake meat or fake cheese or Quorn.) I'd possibly find it a bit too rich - I'd use a plain but highly seasoned bechamel made with veg stock and fresh herbs and just put cheese on top of the final layer. But that's only my taste.
I also like other previous posters' suggestions of a buffet with real cold ingredients that all taste of themselves: nice cold meat with grainy mustard, smoked salmon and some lemon quarters and/or horseradish mayonnaise, decent contrasting-type cheeses (soft, blue, pungent, fresh/mild/crumbly, goat or ewe), olives, grapes, quartered figs, posh little tomatoes, celery sticks and cucumber sticks/slices, sliced avocado in vinaigrette, grated raw carrots in olive oil with lemon, sliced raw apples, clementines, chutney if you like it (I don't) , oatcakes, proper nice bread, unsalted butter, plain crackers such as Bath Olivers. If your guests can be trusted to behave then home-made hummus and home made tabbouleh (both really, really simple), too. Probably cheaper than the equivalent quantity of re-heated packs of beige factory-made party food. And not too much bother to prepare on the day.
To repeat - this is just me saying what I'd prefer. I am not judging anyone, at all.