The culinary sense of the term Wellington applies to a specific preparation of a beef roast encased in pastry. The meat is cooked, cooled, coated with a mushroom paste, then dough, then baked.
A roulade is meat or vegetable rolled around a filling of some sort, then baked or braised. But it can
also be a rolled, filled cake - e.g. jelly roll, buche de noel.
A pasty(pastie) is a single portion savory pie - flesh, veg, or both - in which the filling is completely encased in dough before baking or frying. It is a form of hand pie, as are the empanada, calzone, and
stromboli. Hand pies can also have sweet fillings, usually fruit.
A pot pie is a savory of flesh and vegetables in a thickened sauce.gravy. The filling may be either topped or completely encased in dough before baking. There are also versions using a puff pastry top which is baked separately before being placed atop what is, essentially, a thick stew.