Heat the olive oil in a skillet over medium heat. Once heated, add in the steak, salt, and pepper. Cook until the steak is browned, but not cooked through. Take off the heat.
½ tbsp olive oil, 2 lbs sirloin steak, ½ tsp salt, ¼ tsp pepper
Add the garlic, ginger, sesame oil, brown sugar, soy sauce, and beef broth to the Crockpot. Whisk until combined.
3 cloves garlic, 1 piece 1-inch ginger, 1 tsp sesame oil, ¼ cup brown sugar, ¼ cup soy sauce, 1 cup beef broth
Add in the steak and onion and stir to the coat in the sauce.
1 medium onion
Cover with the lid, and cook for 6-8 hours on low, or 3-4 hours on high.
When there’s a half hour left of cook time, add in the bell peppers and cornstarch slurry.
2 bell peppers, 2 tbsp cornstarch, 2 tbsp water
Cover and cook on high for another 30 minutes until the peppers are tender and the sauce has thickened.