Easy Make Ahead Mushroom Gravy

Ingredients

• 2 cups chicken stock - prefer unsalted
• 1/8 teaspoon freshly ground black pepper
• 1 tablespoon olive oil
• 1/2 cup cremini mushrooms sliced
• 2 cups beef stock - prefer unsalted
• 1 1/2 tablespoons chopped fresh sage or 1/4 teaspoon dry
• 1/2 cup butter
• 1/2 cup all-purpose flour
• 1/4 teaspoon salt
• 2 cloves garlic, minced
• 1/2 cup chopped onion