Sprinkle chicken with salt & pepper. Combine chicken with lemon juice, garlic and dijon mustard. Toss to coat and set aside for about 5 minutes.
Put cooker on saute mode (if available) and spray with cooking spray or olive oil. When ready, add chicken thighs and saute for 3 minutes per side. This step may need to be done in two batches to not overcrowd the cooker. Remove chicken. Add 1 chicken broth and scrape the bits from the bottom of the cooker.
Add chicken back to cooker, close the lid and the venting valve. Select 'poultry' mode for 5 minutes.
When the cooker beeps to indicate 10 minutes is completed, leave the vessel and allow the cooker to natural release steam for approximately 6-8 minutes. Then move the steam valve open, staying clear of the valve. When the handle easily lifts, it is safe to open. Even so, hold face back and remove lid slowly.
Test the temperature of the chicken to ensure it has been cooked to 165F. If making salad - place chicken on a cutting board and cut into smaller pieces.
Toss with arugula, tomatoes, red onion and vinegar. Serve.