My mother gave me her old pressure cooker that must be at least 30 or 40 years old. I used it last night to stew some onions and peppers; and then added some shrimp and mussels. Turned out pretty darned good.
Clean 3 or 4 mixed sweet peppers (green, red, yellow, etc.) Cut into a large dice.
Do the same with a poblano or two.
Peel four sweet onions, and cut a big X almost all the way through, leaving the onion nearly whole.
Put vegetables on rack in pressure cooker along with chicken stock (or water flavored with chicken boullion).
Cook under 15 pounds pressure for 7-10 minutes. Cool under running water.
Place peeled and deveined (and seasoned) shrimp in steamer basket along with a pound of frozen pre-cooked mussels.
Add to pot; cover and bring back to a boil without applying the pressure regulator. Allow to steam for 7 minutes.
Cool the cooker under running water for a couple of minutes; remove ingredients to platter, and serve.