Homemade Meatballs in Creamy Sauce

Name: Homemade Meatballs in Creamy Sauce
Ingredients: 500 g - 700g Minced meat; 1 C - 1 1/2 C panko; 2 eggs; 2 tsp garlic powder; 2 tsp chicken seasoning powder; 2 tbsp parmesan cheese; 1 tsp ground pepper; Paprika (optional); Chopped herbs (optional); 1-2 tbsp cooking oil; 1/3 C thinly sliced button mushroom; 1/3 C thinly sliced shiitake mushroom; 1 tsp garlic powder; 1 tbsp dark soy sauce; 1 tsp sweet soy sauce; 1/2-1 tsp ground pepper; 1-2 tsp chicken seasoning powder or salt to taste; 1/2 C full cream milk; 2 tsp corn flour + 1/3 C water