There are a number of words you can choose here.
The balloons floated over the valley.
The balloons gently drifted over the trees.
As they released them, the balloons flew into the sky.
In the active sense, i.e. when the balloon is being directed, avoid the word drive, and prefer instead either the word pilot, fly or navigate:
The aviator took the controls and piloted the balloon through the storm.
The aviator took the controls and flew the balloon through the storm.
The aviator took the controls and navigated the balloon through the storm.
I would describe the OP's dish as being neither pasties nor patties.
The most well known type of pasties in the UK are called Cornish pasty
Wikipedia defines a Cornish pasty as being:
... shaped like a ‘D’ and crimped on one side,
not on the top. Its ingredients should include uncooked beef, swede
(called turnip in Cornwall), potato and onion, with a light
seasoning of salt and pepper, keeping a chunky texture. The pastry
should be golden and retain its shape when cooked and cooled
![Cornish Pasty](https://i.stack.imgur.com/F9u7l.jpg)
I believe the dish cooked by the OP does not resemble a pasty in the slightest.
Patties don't quite work for me either. There is a popular dish in Jamaica called, interestingly enough, Jamaican patty.
In the article the patty is described thus:
... contains various fillings and spices baked inside a flaky shell,
often tinted golden yellow with an egg yolk mixture or turmeric. It is
made like a turnover but is more savoury.
![enter image description here](https://i.stack.imgur.com/t91aS.jpg)
In Italy this type of stodgy finger food is virtually non-existent and has never really caught on in fashion. However, if an Italian had to describe the OP's snack food, they might describe it as being vol-au-vents. Vol-au-vents are always made from puff pastry, the small, golden-coloured shell cases are usually filled with a creamy savoury filling.
![enter image description here](https://i.stack.imgur.com/jcOsl.jpg)
However, in the UK, as Barrie England pointed out, they would be recognized simply as sausage rolls, i.e., puff, flaky or short crust pastry, filled with sausage meat, rolled and baked in the oven. The most popular rolls are in fact made with sausages, but there are many variations on this theme, and not all of them need to be savoury. Due to their bite-sized portions they'll often be called mini-sausage rolls.
![mini sausage rolls](https://i.stack.imgur.com/YidMA.jpg)
Comparing the photos of the mini-sausage rolls with that of the OP's it seems pretty clear to me that the two snack foods share many similarities.
If one wanted to impress their guests with a fancy sounding name, I'd opt for vol-au-vent and call the mouthwatering dish, Beef and mushroom vol-au-vents. Otherwise, if your guests are unfamiliar with the term Paszteciki, I would suggest the more British sounding Spicy beef mushroom rolls
Best Answer
Preface ADDED 14 Jan/Jan 14, 00:11 GMT/UTC: This answer, as the OP Lucian Sava is well aware, has been written from an AmE perspective. Actually, it is written from the perspective of the variety of AmE that I speak. I think Lucian gets by now that English usage is not universal, as I had already indicted in my anwer. Let the conversation continue, by all means!
Serpentine is fine, but in English I am pretty sure we would use it as an adjective describing the road. Such a road is also called, in familiar terms, a curvy mountain road. More technically, it is any road that contains many switchbacks or hairpin curves
Switchback can refer to entirety of such a road. But this may not reflect universal usage.
I think serpentine (adjective) would be the more universally recognized word.
You can do an image search for both "switchback road" and "serpentine road" and get many of the same images.
Thus saith the snake: