There seem to be a lot of food ingredients that now seem essential to Old World cuisine that were unavailable before the Colombian exchange. Can we discuss what some of the most important and what they replaced?
Corn (maize)
Potatoes
Sweet potatoes
Tomatoes
Chilis (including sweet peppers/capsicum)
Turkeys
Chocolate/cocoa
Vanilla
Tobacco (stretching the definition of food ingredients to consumables)
Cassavas
In England, potatoes have long been a staple. Before that (and post, I think) it was heavily based on grains, made into bread and vegetable/grain stews (pottage).
I’m surprised at how popular corn is in Korea; it’s in every salad and on most pizzas, and the steamed ears they sell at street vendors is a weird kind that’s unpopular in America. By contrast, during the Berlin Airlift, Germans were insulted to get corn in their care packages because they regarded it as food for pigs and cows, not something humans would eat. I think the English feel about halfway between these extremes about it.
It’s hard to imagine a world without french fries (potatoes). They’re available in so many countries with burgers. Burgers & fries seemed to arrive at similar times. I can’t think of anything else that would be paired with a burger.
Are sweet potatoes really that important an addition? Many parts of the old world had a variety of sweetish, starch-laden tubers. Taro root in the far east and yams from southern Africa are two examples that had spread widely prior to standardized contact with the new world.
Vanilla didn’t really replace anything. The kind of thing where it’s used, like custards and baked goods, used to be spiced with a variety of flavours but no one dominant one. So cookies might be lightly spiced with cinnamon and ginger, a custard may be flavoured with elderflower, or a creme would just be eggs and sugar and cream. If anything, possibly “treacly” would be what it replaced, since a lot of sugar would have been less refined.
3 old world plant foods the OP missed:
common (Phaseolus) beans (which largely replaced broad beans in a lot of cuisines)
Peanuts, which have largely replaced other ground nuts
Squashes and pumpkins (Cucurbita pepo) mostly replaced other gourds
In fact, a lot of modern American sweet potato recipes are actually adaptations of yam recipes. They were eaten by native Americans, but their popularity is largely from Africans (especially in the Caribbean) attempting to re-create their traditional cuisine using local ingredients.
Most strawberries varieties grown commercially everywhere in the world are hybrids of New World species. They have largely replaced wild-type European strawberries in cuisine.
If you’re going that route… most of Europe’s wine grapes grow on North American root stock, because the North American grapes are immune to a pest that nearly wiped out Europe’s grapes (a negative trade of the Columbia Exchange). The only way to save the grapes of Europe was to graft them to American roots.