Turn on the sauté feature of your Instant Pot and add the oil or butter. When heated, add the onions and sauté until slightly translucent, about 2-3 minutes.
Now add the garlic, thyme, oregano, smoked paprika and crushed red pepper. Sauté for about a minute.
Add the carrots and celery. Sauté 1-2 minutes.
Cancel the sauté function and add the broth, split peas, liquid smoke, bay leaves, salt, and pepper.
Close and secure the lid. Turn the steam release handle to the Sealing position. Push the Pressure Cooker (Manual Setting) button to high pressure and set the time to 15 minutes by using the + or - button. The screen will then display ON while the preheating is in progress (this could take 10-12 minutes). When the Instant Pot has come to pressure, you'll see the 15 minutes displayed on the screen again.
The cooker will beep when the time is up. Don't touch anything, just let the pressure naturally release for another 15 minutes. Now carefully turn the steam release handle to the Venting position (It will loudly spurt out lots of steam and some water). Once the Float Valve goes down you can carefully open the lid.
Remove the bay leaves and taste for seasoning. Add more if needed. Let the soup sit a minute before serving. This will give it time to thicken up. If it's too thick for your taste, you can add a small amount of vegetable broth. *See notes stovetop instructions.
In a large pot over medium heat, sauté the onions and celery in butter or oil until softened, about 5-6 minutes.
Add garlic and seasonings, sauté for 1 minute
Now add carrots, broth, splitpeas, liquid smoke salt, and pepper. Turn up the heat to bring to a boil, then reduce heat to a low simmer. Cook uncovered for 1 1/2 - 2 hours until peas are completely softened. Stir occasionally.
Taste for seasoning and add more if needed. Let the soup sit a minute to thicken. Serve as is or blend for a super smooth texture.