"A great way to put that bumper crop of homegrown tomatoes to use and is prepared all in a pressure cooker. Use any variety (including multiple varieties) of tomatoes to make a unique flavor every time. You can also vary the Cream Cheese and Brie ratios so long as the total remains about 8oz of cheese total. I also prefer fresh spices over dried if you grow your own. This recipe is intended for pressure cookers that have an automatic "soup" setting but can be altered for standard pressure cookers."
Select the soup setting on the pressure cooker and heat the oil and butter until the butter melts. Add the onion, celery and garlic and cook, stirring occasionally, until the onions and celerey are soft (about 5 minutes).
Add your tomatoes, thyme, basil, chicken broth salt and pepper and stir until mixed. Seal the pressure cooker and cook (if the pressure cooker timer had already started while cooking the onions reset it to get the full time suggested by your pressure cooker which should be about 5 minutes).
Once the cooking has completed if there is an automatic "warm" setting on your cooker let it go for about 25 minutes. If there is no warm setting you should cook on medium for another 15 minutes and then allow the contents to cool with no heat for a final 10 minutes.
Carefully release any steam (there should be very little) and remove the cooker lid. Use an immersion blender to puree soup for about a minute. Add the brie and cream cheese and blend some more until the mixture is smooth.
Strain the soup twice for a clean/smooth texture and taste for acidity. Add baking soda a pinch at a time and stir well--tasting after every pinch. Use only as much baking soda as needed to reach your desired acidity level.