Is it possible to fry vegetables in cream?

Short answer: cream is far from ideal as a frying medium.

In the US at least, heavy cream is about 35% milkfat. Recently, I have learned the UK has a product called double cream which is closer to 50% milkfat.

So what is the rest of the cream, if it is only 50% milkfat at the high end? It is water, with dissolved milk solids and minerals.

Even butter is only about 80% milkfat--the rest is an emulsion of water and milk solids in the main milkfat phase. When butter is made, one by product is buttermilk (the old fashioned kind, as opposed to the modern cultured milk product) which is the remainder of the liquid components in the cream after the butter precipitates. The essence of making ghee is separating the milkfat from the other components.

What does all of this mean? Cream would be far from an ideal medium for frying, as the water would have to evaporate before the temperature could rise to frying levels.

It may be possible in some way by reducing the cream until only essentially the fat is left, and then frying in that, but it doesn't seem very practical. I am not sure how you would do it without introducing many off flavors from scorching or burning the milk solids. I could not find any references to such a thing when googling, although the results for fried ice cream did tend to predominate.

If you want to fry in cream--use ghee. It is highly concentrated milkfat.

No, you cannot fry in cream. But you can cook your vegetables in it.

There are three types of "real" frying: deep frying (you submerge food in a very hot oil bath), shallow frying - you put a thin layer of fat on a very hot pan and sear a big piece of food on the pan, e.g. a steak, and stir-frying - you have an even hotter pan/wok and keep moving small pieces of food in it, with only a bit of oil. None of these can be done with cream (or with pure butter for that matter) because the milk solids will scorch and the water will splatter.

But many people tend to call any technique involving a shallow pan on a hob "frying". This is technically not correct, but you can still hear things like "mushrooms fried in cream". Normally, it involves first sweating the vegetables a bit so they get a bit of color, and then covering them in cream and cooking until softened. The temperature is much lower than in frying, and the result are tasty, soft vegetables swimming in tasty reduced cream which has absorbed the vegetables and herb flavors. Alternatively, you can use cream for braising. Both give good results, and both are sometimes called "frying". So if you find a recipe for "frying" vegetables in cream, and it looks like one of those, give it a try. Just pay attention that the temperature stays mid-range, not as high as for real frying.

Maybe you could poach them in a sort of double-boiler arrangement. The problem is that the cream will begin to separate as it starts to boil. It'll hold together for a while, but probably not long enough to fully cook a vegetable, or to get a browning.

The fat that collects on boiled milk is, as was pointed out, closer to ghee than to cream. Try frying the vegetables in butter, ghee, or oil, and then adding heavy cream near the end of cooking to form a sauce.

You absolutely can fry in cream, and it has several advantages over oil. Food52 and Ideas In Food have plenty of recipes that all work great. https://food52.com/recipes/81961-caramelized-cream-eggs-from-ideas-in-food