Be it stove-top or pressure cooker, this'll come out deeelicious.
On saute setting saute onion. Toss beef in cornstarch and brown with onions in instant pot until onions are softened and beef is browned- just a few minutes.
While beef is browning, in a separate bowl add water, bouillon and white wine or rice wine vinegar.
If choosing option to microwave broccoli do it now. In microwave steam chopped broccoli for 6 minutes. Remove access water.
When pressure cooker is finished combine broccoli with beef and sauce.
If choosing to cook broccoli in pressure cooker add to pressure cooker, cook one minute and quick release.
Serve over rice.