what is the key to making TENDER beef tips. my flavor is good but they are usually tough. I normally use sirloin and slow cooker and cook for 6 hours on low. normally flavor with some sort of onion mushroom gravy mix. any ideas.

My wife does them in the crock pot on low for 5 hrs, and seasons with:

Pack of brown gravy, 1/2 cup water, cream of mushroom, dales and worcestershire sauce

Pressure cooker is the key. Just use beef stew meat Season with seasoning salt, cover in water & a little oil in cooker. When it starts jiggle cook about 25 minutes, then mix in mushroom gravy packets accordingly to the amount of meat add a little more water if needed
(Have add a can of cream of mushroom it makes it creamier )

thanks guys

You need to sear them at a high heat first in a small amount of oil with a very light dusting of flour then put them in your slow cooker. Searing them will seal in the moisture that will otherwise escape during the slow cooking process.

Love some beef tips.