Break the bunch of pasta in half and lay flat in the bottom of the pasta cooker. Add the salt and 1 cup of water; shake gently from side to side to mix.
Microwave uncovered for 6-7 minutes, watching carefully to be sure that the pasta doesn't dry out (add another 1/4 cup of water if it does). Stir after 3 minutes to break up any clumps of pasta.
After 6 minutes, check the texture of the pasta to see if it's done to your liking: after the microwave has turned off, open the door and let the pasta cooker sit for ~10 seconds. Carefully remove the cooker from the microwave using the handles of the pasta cooker. Use a fork to remove a single strand of spaghetti; check its texture. Return the cooker to the microwave, if necessary, and continue cooking as needed until the spaghetti reaches your desired texture.
*To measure the pasta, make a ~1/2" circle with your index finger and your thumb: cook the pasta that you can fit into the circle!
**If there IS a lot more liquid than about a tablespoon, carefully drain the excess. You can also microwave for an extra 30 seconds, which will allow the pasta to absorb some of the remaining liquid. If there's LESS than a tablespoon left in the cooker, don't sweat it: the pasta will still be great!
***If you are adding tuna or cooked chicken, you may want to cover and microwave for 20 seconds after you add it to the pasta.