Heat your pressure cooker over a medium-high heat, then add some oil. Working in batches, brown the beef cubes on all sides in the oil then transfer the browned cubes to a plate. Add some more oil if necessary and cook the onions over a medium heat until they are tender and browned. Add the garlic and peppers to the onions and cook, stirring constantly, for 3 minutes.
Add the chili powder, cumin and hot red pepper flakes if using.
Cook, stirring constantly, for 2 minutes or until fragrant.
Pour in the beer to deglaze the pan.
Those stuck-on bits you scrape up will add to the flavor.
Put the beef back in the pressure cooker and add all remaining ingredients except sour cream and cheese.
Drain and rinse the beans before adding those.
Bring up to pressure and cook the chili for 20 minutes.
Let it stand for about 10 minutes to release the pressure and finish cooking.
If the chili is too thin, just simmer uncovered for another 15 minutes to thicken it up.