Heat oven to 400° F.

Slice the tomatoes in half and lay skin side down on a baking sheet.

If you want to roast your garlic, cut the top off of a head of garlic bulb and set it on the baking sheet with the tomatoes.

Pour the ¼ cup of olive oil and 3 tsp Kosher salt over the tomatoes. Toss to coat all of the tomatoes and the garlic bulb (if roasting garlic).

Roast in oven for 40-50 minutes. Then remove from oven and set aside (keep it all on the baking sheet).

If you roasted the garlic, remove the roasted cloves from the bulb and set aside so they are ready to add to the soup.

Turn on the pot's Sauté setting. When it is hot, add the remaining 2 Tbsp olive oil and the butter. Add in the onions and cook, stirring occasionally, until translucent.

Add the garlic (roasted or fresh), and red pepper flakes. Stir and sauté for about 30 seconds.

Add the tomatoes (and all of the juices from the pan, if roasted), the remaining 1 tsp salt, rosemary, thyme, and basil leaves, pepper, chicken broth and parmesan rind, if using. Stir.

Put the lid on the pot and set the steam release knob to the Sealing position. Turn off the Sauté setting and press the Pressure Cook button or dial, then the +/- button or dial to select 8 minutes (if using roasted tomatoes), or 20 minutes if using fresh.

When the cook cycle is finished, turn the pot off so it doesn't enter the Warming cycle. Let the pot sit undisturbed for 15-25 minutes to naturally release the pressure. Then turn the steam release knob to the Venting position to manually release the remaining steam/pressure.

Open the lid and gently stir the soup. Remove parmesan rind, if using. Use an immersion blender to smooth the soup, but not too much, unless you want a completely smooth texture.

Taste and adjust salt, if needed.

Serve hot with some crisp croutons, extra fresh basil leaves, parmesan, or sour cream.