Place all of your veggies, from the broccolini to the garlic cloves, into a large bowl. Drizzle with 1 TBSP of olive oil and sprinkle with the Italian seasoning. (If the Italian seasoning blend you're using doesn't include salt, make sure to add some salt to taste. Start with 1/4 tsp.) Toss the veggies until everything is evenly coated with oil and seasoning; set aside.
Set your Instant Pot to sauté mode. Drizzle in the other 1 TBSP of olive oil and let it heat up a bit (you won't have to wait long since the IP heats up very quickly).
Add the vegetables and simmer, stirring occasionally, until they're tender—about 5-7 minutes. Once tender, transfer them back to their original bowl and cover them to keep them warm. Turn off the sauté function.
Add the broth and penne to the Instant Pot. Give it a quick stir. Place and lock the lid down, set the valve to to "sealing", and cook on manual high pressure for 5 minutes, or half the time it states on the package's instructions (cooking pasta in the IP seems to work best when you halve the regular cooking time and round it down. So if the package says 11 minutes until al dente, go for five minutes. If it says 15 minutes to al dente, go for 7 minutes, etc.) When done, do a quick release.
When you open the IP, scoop up 1 cup worth of the broth and set aside. Drain the rest. Add the pasta back to the IP. Toss in the vegetables and reserved broth, and give it a stir. Finally, add the cheese, and stir to combine.
Serve immediately; garnish with freshly chopped basil or parsley if you wish!