How do I make a stuffed pasta dish?
It depends what you mean by a stuffed pasta dish. The two things that come to mind are cannelloni and ravioli. For the first, you'd purchase cannelloni pasta and cook slightly under the suggested time on the package (it will continue cooking in the oven). Then, in the most traditional form, stuff the pasta with a ricotta mixture, which you can easily do using a pastry bag or ziploc with the end snipped off. Top with marinara or other sauce and bake.
For ravioli, you could purchase fresh pasta sheets or make them. You'd then put dollops of your stuffing mixture, which could range from ricotta to sauteed vegetables and many things in between, a few inches apart starting an inch from the edge. Cover with second sheet of pasta, using egg wash to seal, and cut with pizza cutter into squares. Boil and top with sauce of your choice.
There are likely many recipes for both on this site, which will give more detailed and concrete directions.
Home-made cannelloni pasta
You could also make stuffed shells - buy jumbo pasta shells, boil them, then rinse under cool water. Stuff them with a ricotta mixture (add some salt and pepper, chopped herbs, minced garlic, and parmesan cheese). Then bake them, lay them in a casserole dish, cover with tomato sauce and grated mozzarella and bake at 400 until the cheese melts. Easy!
My husband and I made this dish --
It was fabulous and fun to make, and delicious. We couldn't find paccheri (I didn't look all that hard, to be honest) so we just used rigatoni and it worked out. Although I didn't do the heavy lifting of stuffing the little tubes, so my husband might say to make the effort to find the paccheri, since they're bigger!
I recommend roasting some pumpkin and adding it to your ricotta filling mix with your herbs of choice. So good!! I have a great recipe for home made cannelloni with this filling and a bechamel sauce at home. I'll try to post it later!