1Season your beef with SPG or your favorite seasoning. Heat a skillet over high heat with the butter and sear the beef in small batches for 1-2 minutes per side.
2Transfer the beef to the crockpot. Deglaze the skillet with a splash of the measured beef broth, scrape up those browned bits, and pour everything into the crockpot.
3Add the remaining broth, shoyu, brown sugar, garlic, ginger, sesame oil, and black pepper. Stir gently.
4Cover and cook on LOW for 4 to 5 hours or HIGH for 2.5 to 3.5 hours.
5Mix the cornstarch slurry with a cup of broth. Stir the slurry into the sauce and cook on HIGH for 15–20 minutes, until thick and glossy.
6Slice the green onions into 1 inch pieces. Separate the precooked noodles and add them directly to the crockpot. Toss everything together and heat on HIGH for 5–10 minutes.
7Finish with sliced green onions, sesame seeds, and chili crisp oil if you want some heat then serve immediately.