Heat 1 teaspoon olive oil in a pressure cooker over medium heat. Add sausage meat and cook until browned, breaking it into crumbles. Remove sausage to a plate and drain any dripping.
Add remaining teaspoon of olive oil to pressure cooker; cook onion and garlic until onion is transparent. Add barley and stir 1 minute. Return sausage to pressure cooker. Add lentils, chicken, parsley and stock to cooker, adding enough stock to completely cover chicken.
Close cover securely; place pressure regulator on vent pipe. Bring pressure cooker to full pressure over high heat (this may take 15 minutes). Reduce heat to medium high; cook for 9 minutes. Pressure regulator should maintain a slow steady rocking motion; adjust heat if necessary.
Remove pressure cooker from heat; use quick-release method following manufacturer's instructions or allow pressure to drop on its own. Open cooker and remove chicken; shred meat and return to soup. Add chickpeas, spinach and salsa; stir to blend and heat through before serving.