Why didn't I think of that question...
Here's a few favourites:
- Petrine Christianity wins out. If Christianity still conquers Europe, that basically means kosher for everyone (well, not really, but many of the dietary restrictions of Jewish tradition would still apply through much of Europe.) I could certainly not see either the widespread use of pork nor the free mingling of dairy and meat cookery, both of which are mainstays of medieval (and modern) European cuisine. Europe (and by extension its colonies) would eat a lot more like the Graeco-Romans, with plenty of fish, many 'neutral' veggie dishes, oil rather than butter, and much leaner meat. That might not be altogether bad...
- The wheat frontier stays south. Wheat and wheat bread became a status symbol in northern Europe in the course of the early middle ages, leading to the use of much prime land for low-yield wheat rather than hardy, high-yield rye and oats. The 'bread dependency culture' of the later middle ages might not materialise, and with better land utilisation, many of the persistent local and regional famines could be avoided. Of course, it would also mean more people eating porridge and knackebrod, but that's healthy (and anyway, good knacke is a real treat). A northern diet based on buckwheat porridge, rye bread and oatcakes (as oppoased to the southern wheat bread) remains common to this day. Germans eat breakfast porridge rather than breadrolls. As an aside, no breadcrumbs used for thickening sauces means either an earlier development of butter-flour´thickener or the increasing use of boiled-down fruit sauces.
- Reduced Germanic influence in late antiquity. Germanic status foods were meat, mead, and beer. The central role of meat, and much of it, top this day retains its position in the European diet. By contrast, the diet of the Romans (especially the refined eating of the upper classes) had developed a marked tendency towards vegetarianism, and a strong appreciation of expensive fish inherited from Greece. If this had prevailed, Europe's seas might be emptier yet, and her pastures still forests.
- Conversely, with stronger Germanic influence and, maybe, no Lenten fast, fish is almost completely removed from the table and to this day remains poor man's fare. That basically removes the raison d'etre of an entire Canadian province
- no beet sugar processing until WWI or WWII. This might taint beet sugar with the association of 'ersatz wartime food' rather than present it as 'a breakthrough of modern science' as was done in the 19th century. Central Europe still imports most of its sugar from Latin America and Africa, adding to the region's slightly greater prosperity. Cane sugar shortage became a serious issue in many Communist states in the 80s.
- No humoral pathology. This would have huge repercussions for European culture (especially if we posit the Empiricist school of medicine won out instead), but for foods this would lead mostly away from certain ideas that define European cuisine to this day. Firstly, a distrust of powerful flavours would not develop. Europe is almost unique in the relative blandness of its upper-class cuisine. Compare the liberal use of spices and sweeteners in Arab, Chinese, Thai, Indian or South American cookery. That is because the medical opinion of centuries militated against imbalances. Lower-class cuisine (and those areas mercifuilly untouched by the authoritry of those doctors) retained a fuller appreciation of the glories of sorrel, vinegar, garlic and onion. Imagine a Europe where plentiful garlic, salads, strong marinades and fiery sauces held uncontested sway. The same goes for raw fruit and vegetables - dangerous, according to the professionals.
- This comes closer to ASB, but what if (for some reason) pigs were not domesticable? Without this easy, handy source of animal protein, many parts of the world would suffer real shortage.
- An earlier introduction of maize and potatoes into Europe could have averted several hunger crises - including, possibly, that of the 1780s. Conversely, a later one might make the 'hungry 40s' much hungrier. Industrialisation might benefit from workers being literally starved into submission, or the whole edifice of bourgeois society could come crashing down...
- If the South won the Civil War (yeah, couldn't resist), would the great herds of Texas still be shipped to the stockyards of Chicago? Would beef become a national staple at a later date? Or at all? Would the resentful CSA export its bully beef tins from vast slaughterhouses on the Gulf Coast to Britain, leaving the US dependent on the beef of Minnesota and imports from Argentina?
- Distilled alcohol stays a medical preparation. The role of hard liquor in the pacification and mobilisation of Europe's underclass should not be underestimated (the large-scale production of brandy and gin in the 1400s created what can best be described as a drug crisis, complete with attendant petty crime, prostitution, and human misery). Until the late 19th and 20th centuries, millions of poor found solace in a shot of hard stuff or three. I am also convinced that liquor played a role in the mad courage of Europe's conquerors abroad, and we don't need to mention the effect its introduction had on native populations throughout the world.
- Finally; what if there was a large, edible species of insect grub in Europe? Oh, I think we had that already...