Preheat the oven to 425℉. Line a baking pan with parchment paper or spray with cooking spray.
Peel and cut the sweet potatoes and carrots, Then wash and cut the red peppers and leeks. Peel the cloves of garlic and leave whole. Place all those vegetables onto the baking pans. Drizzle olive oil over the vegetables and then season with salt and pepper.
Put the vegetables in the oven to roast for 20-35 minutes. Remove the red peppers, leeks, and carrots earlier if they are getting too roasted so they don't burn. Remove vegetables when roasting is complete and set aside. If you don't want to take the time to roast the vegetables, you can put them into the Instant Pot without doing so. However, roasting the vegetables adds rich flavor.
Press saute on the Instant Pot and wait for the screen to show HOT. Then the 4 Tbsp. of butter and melt. Add onions and saute for 2-3 minutes until they soften and begin to get translucent.
Add part of the chicken or vegetable stock and deglaze the pot (scrape off any bits stuck to the bottom of the pot). Next add the roasted vegetables, the rest of the stock, 2 tsp. smoked paprika, 1/2 tsp cayenne pepper, two cinnamon sticks, bay leaves, and salt and pepper to taste.
Close and seal the pot and cook on High pressure for 5 minutes. When cooking is complete, perform a quick pressure release and open the lid unless you didn't roast the vegetables first. If the vegetables weren't roasted, leave the pot for a natural pressure release for 12 minutes before opening the pot.
Remove the bay leaves and cinnamon sticks and dispose of them. Transfer the soup in batches to a blender and blend the soup to break down the vegetables then pour into a bowl until all of the soup is blended.
Pour the blended soup back into the Instant Pot and press the Saute button Taste the soup and add salt and pepper as needed. Add the 2 Tbsp. of soy sauce, 2 tsp. of fish sauce, lemon juice, and 2-3 cups of half and half and stir. Taste again and adjust seasoning as desired.
Put the sour cream in a squirt bottle. Ladle soup into a bowl, squirt a swirl of sour cream in the middle, sprinkle with green onions, and enjoy.
Notes
If you don't have an Instant Pot or don't have one large enough this recipe could also be made in a pot on the stove (or you could cut the recipe in half) ^_^ After roasting the vegetables, follow the rest of the instructions using a pot or dutch oven. Allow the soup to simmer until the celery is tender.