Slow Cooker Pepper Steak: Tender Beef in a Flavorful Pepper Sauce

Slice the beef against the grain into thin strips. This will help the steak become tender while cooking in the slow cooker.
In a large pan, heat the olive oil over medium-high heat. Sear the beef strips in batches for 2-3 minutes per side until browned. This step helps lock in the flavors but is optional.
Add Ingredients to the Slow Cooker:

Transfer the seared beef strips to the slow cooker. Add the sliced onion and bell peppers on top of the beef.
Add the minced garlic, soy sauce, Worcestershire sauce, oyster sauce (if using), and beef broth. Stir to combine.
Sprinkle in the freshly ground black pepper, ginger (if using), and sesame oil (optional).
Cook the Pepper Steak:

Cover and cook on low for 4-6 hours, or on high for 2-3 hours, until the beef is tender and the flavors have melded together.
Thicken the Sauce:

About 30 minutes before serving, mix the cornstarch with a little cold water to make a slurry. Stir this mixture into the slow cooker to thicken the sauce. Cook for an additional 30 minutes, or until the sauce reaches your desired thickness.
Serve:

Once the pepper steak is done, give it a final stir and serve it over hot steamed rice or noodles. Garnish with fresh chopped green onions or sesame seeds if desired.
Serving and Storage Tips: