Drain juice from clams into a large measuring cup; set aside. If you’re using fresh clams, buy a bottle of Clam Juice to use.
Melt butter in skillet. Add clams, garlic and onions. Saute for 1 1/2 – 2 minutes, then add a quarter of the clam juice. Keep skillet on medium-high and cook until clam juice has reduced.
Add the next quarter of the clam juice and proceed as above, until all of the clam juice has been used.
Cook the pasta according to package directions. When pasta & sauce are finished, toss to combine, top with cheese. This dish makes great leftovers as well.