To make the vinaigrette, whisk together the red wine vinegar, Italian seasoning, honey, mustard, salt, and black pepper. Add the olive oil, while whisking. (Alternatively, you can combine all of the ingredients in a jar with a tight lid and shake until the vinaigrette is smooth.)
Combine pasta, water, and salt in the bowl of an Instant Pot. Give everything a stir.
Close and lock the lid.
Set the pressure valve to Sealing.
Pressure cook on high for 4 minutes.
Leave the pasta on natural release for exactly 5 minutes. (Note: Be very careful not to let it sit for any longer or the pasta will overcook.)
Use manual release to release any remaining pressure. (Note: Hot and starchy pasta water may spray out of the pressure valve when you release it. Cover the valve with a dish towel as it releases to keep this contained and minimize the mess.)
Open the lid and add half the vinaigrette (reserve the other half). Give the pasta a good stir, 20 to 30 times. (This will get rid of any dry spots that remained where the pasta was sticking out of the water during cooking. If adding sauce, stir it in at this point.)
Return the lid to the top of the pressure cooker (no need to lock it just set it on top) and leave the pasta for 5-10 minutes more. (Note: This step is the most important because the pasta will absorb the vinaigrette and any remaining liquid. It will also continue to cook just a bit in the residual heat of the machine. This is the key to pasta that is cooked, but not overcooked.)
Unplug the machine (or turn it off completely so that it is no longer warming). Remove the lid and let the pasta cool completely. (You can transfer it to another bowl if you want to cool it down more quickly.)
Just before serving, stir the salami, cheese, tomatoes, remaining vinaigrette, and basil into the pasta.
Serve at room temperature or slightly chilled.