Saut chicken garlic and onion in olive oil in the instant pot
Add soy sauce, hoisin sauce, brown sugar, chicken broth, water chestnuts and peppers
Break spaghetti noodles in half and place on top of mixture making sure all noodles are under liquid
Set instant pot to manual high pressure for 5 minutes. Quick release and add steamed broccoli, mixing everything together.
Mix 4 tablespoons cornstarch with enough water to make a thick slurry.
Set instant pot to saut and stir in cornstarch slurry until sauce thickens.