Combine Chinese 5-spice, kosher salt and black pepper.
Rub chuck roast all over with spice mix.
Sear chuck roast in hot sauté pan with avocado oil, 2 minutes on each side.
Place carrots in bottom of slow-cooker.
Remove chuck roast from pan and place on top of carrots.
Deglaze pan with mirin, tamari and beef stock.
Add fresh ginger and garlic to pan, simmer for 3 minutes.
Add onions, mushrooms, bok choy and red peppers to slow-cooker.
Pour liquid from pan on top of vegetables.
Cover and cook for 5-6 hours on high setting or 10-12 hours on low setting.
15 minutes before serving, add sugar snap peas.