Ingredients:
- 2 lbs ground beef chuck (80/20)
- 1/2 cup Panko breadcrumbs
- 1/4 cup whole milk
- 1 large egg, beaten
- 1 tsp garlic powder
- 1 tsp onion powder
- 1/2 tsp black pepper
- 1 tsp kosher salt
- 1 tbsp Worcestershire sauce
- 2 cups low-sodium beef stock
- 1 large yellow onion, thinly sliced
- 8 oz cremini mushrooms, sliced
- 2 tbsp ketchup
- 1 tsp Dijon mustard
- 3 tbsp cornstarch
- 3 tbsp cold water
Instructions:
- Combine 1/2 cup Panko breadcrumbs and 1/4 cup whole milk in a large bowl. Let the mixture sit for 2 minutes to form a panade.
- Add 2 lbs ground beef, 1 beaten egg, 1 tsp garlic powder, 1 tsp onion powder, 1/2 tsp black pepper, 1 tsp salt, and 1 tbsp Worcestershire sauce to the Panko mixture. Mix gently by hand until just combined; do not overwork the meat.
- Gently roll the mixture into roughly 1.5 inch meatballs. Do not overwork the meat or it will become tough.
- Heat a splash of oil in a skillet over medium high heat and brown meatballs for 2-3 minutes per side until a dark crust forms.
- Remove meatballs, then add 1 sliced yellow onion and 8 oz sliced cremini mushrooms to the same pan. Cook until onions are translucent and soft.
- Pour a splash of the 2 cups beef stock into the skillet, scraping up the brown bits from the bottom.
- Place seared meatballs into the crockpot, then top with the onion and mushroom mixture.
- Combine the remaining beef stock, 2 tbsp ketchup, and 1 tsp Dijon mustard; pour this over the meatballs.
- Cover and cook on Low for 4 hours until meatballs are tender and fully cooked.
- Mix 3 tbsp cornstarch with 3 tbsp cold water; stir into the slow cooker 20 minutes before serving until the gravy is thick and glossy.