Bring a large pot of salted water to a boil. Add the potatoes, stir, and boil for 3 minutes before adding the pasta, then cook together until the potatoes are just tender and the pasta is firmly al dente, 3 to 4 minutes. Drain and set aside.
In a large sauté pan over medium heat, melt the butter. Stir in the onions and bacon and cook until the onions become translucent and the bacon has rendered its fat, 5 to 7 minutes. Pour in the white wine, stirring to loosen any caramelized onion or bacon bits. Turn the heat to high and simmer the wine until slightly reduced, about 1 minute. Add in the vegetable broth and cream, followed by the potatoes and pasta.
Bring to a boil, then turn the heat to low and simmer until almost all of the liquid has been absorbed, about 10 minutes. Season with salt and pepper and stir in the minced parsley.
Divide the pasta-potato mixture into individual ramekins or transfer to an ovenproof serving dish, then sprinkle with the grated cheese and broil until nicely browned, about 3 minutes, keeping a watchful eye on the proceedings.