Season both sides of your steaks with the paprika, onion powder and steak seasoning.
Heat a large skillet over medium high heat and sear the steaks quickly on both sides. You are just looking to get a little color not cook them.
Remove the steaks from the pan and place into the bottom of your slow cooker.
To the pan add your butter, onion and mushrooms.
Stir this around until the onions and mushrooms pick up the steak bits from the bottom of the pan.
Toss in your garlic and flour and stir everything together for 1 minute.
Add this mushroom onion mixture to the slow cooker.
Next in a small bowl combine one brown gravy mix, water, worcestershire sauce and brown sugar. Whisk to combine.
Pour this into the slow cooker.
Cover and cook on low 6 hours or high 4 hours or until the meat is tender.
Remove the steak from the slow cooker.
Whisk in the second envelope of brown gravy mix. Add sliced peppers and stir until coated.
Add the steak back to the gravy.
Serve over rice or mashed potatoes.