I would like to point out that Betsy's hypothesis is incorrect. It's silly to waste all this energy dichotomizing (that's a horrible word, just for you, Betsy) food. Food doesn't (and shouldn't) come with an immutable "like" or "don't like" tag.
For instance, I don't really like cake. If we're at so-and-so's birthday party, it's a lot easier just to eat cake like everyone else than it is to politely (and awkwardly!) excuse myself from the cake-eating bit. So it's probably better if I don't bother telling you I don't like cake, which means there's no reason for me to think about whether or not I like cake.
So mostly I just eat food and don't think too much about whether or not I like it.
To get to Betsy's argument:
First off, I don't have any problem with pasta primavera. Betsy and I have had conversations that go something like this:
Betsy: I bet we could sautee [list of vegetables] and put it on [specific type of pasta].
Mary: Isn't that the same thing as pasta primavera?
How that translates into not liking pasta primavera, I don't know.
Second, beans. I don't really like beans (in general). Betsy loves beans (in general). Black beans and pinto beans taste pretty much the same to me (mushy) and black beans don't start with P. I have put pinto beans in things, though, voluntarily, without prompting from Betsy. (I do like green beans, though, especially fresh/raw. You pop them in your mouth and they go crunch, crunch.)
Third, pesto. Greens and nuts aren't supposed to go together. I also don't really like almonds. I like cashews, pecans, and peanuts (two of which, by the way, begin with P), but what makes them good is the soft munch, munch in your mouth. If you grind them into pesto, they don't go munch, munch the same way. (I do like peanut butter and basil sandwiches, a desperate I'm-out-of-almost-everything college discovery I made last year.)
Fourth, I like peaches, pears, plums (probably - it's been a while since I've had plums), potatoes, pasta, pepper (as a seasoning), pecans, pancakes, and lots of other things that start with P.
I don't really like penne pasta, though (score one for Betsy), because I don't really like tube pasta much. I don't really like popcorn, either, but that's because I almost choked on a kernel once. Popcorn doesn't really taste like anything, anyway, unless you put salt, butter, or cheese on it. Then it tastes like salt, butter, or cheese. I don't really like pop, either, but Betsy doesn't get a point here because it's soda where she comes from.
I also like tomatoes.