Prepare the slow cooker with nonstick cooking spray. Place the steak strips into the bottom of the slow cooker.
In a medium bowl, whisk together the garlic, ginger root, soy sauce, brown sugar, oyster sauce, and chili paste.
Add the carrots and onion to the slow cooker and toss with the meat.
Pour the sauce over the meat and vegetables. Toss to coat.
Cover and cook on low for 4 hours.
Add the remaining vegetables to the slow cooker and stir to combine. Re-cover and cook for an additional 30 minutes or until the vegetables reach desired tenderness.
Meanwhile, cook the spaghetti according to the package directions. Drain and immediately drizzle with sesame oil.
Just before serving, add the cooked spaghetti to the slow cooker and toss with the meat, vegetables, and sauce.
Serve garnished with sliced green onions, if desired.
Notes
How can I make this vegetarian?Use tofu instead of beef, omit the oyster sauce, or exchange it for vegan mushroom sauce.What is the difference between chow mein and lo mein?In short, it comes down to the type of noodle. It also depends on how it is cooked. Lo mein means tossed noodles, while chow mein means fried noodles. While we aren't frying this dish, we add sesame oil to get that fried flavor.Can I freeze this?This dish is best eaten as fresh as possible, meaning it's not very good frozen. You can refrigerate the leftovers at most, but they should be eaten within a few days.Can I use different meat?Although we chose flank steak strips, you can also use beef stew meat or cooked ground beef.