Kuah Jamur (mudah, dari awal, tidak perlu menetes)

Bahan-bahan (5 porsi)

• 1 tbsp olive oil
• 45 g / 3 tbsp butter (, unsalted)
• 1 1/2 tsp garlic (, finely minced (~1 large or 2 medium cloves))
• 400 g / 14oz mushrooms (, sliced 3mm / ⅛" thick (white/button or Swiss/Cremini))
• 1/4 tsp salt
• 1/8 tsp black pepper
• 30 g / 2 tbsp butter (, unsalted)
• 4 tbsp flour (, plain / all-purpose)
• 2 cups beef stock / broth
• 1/4 tsp black pepper
• Salt (, to taste)