Preheat oven to 350 degrees F (175 degrees C). Butter a casserole dish.
Whisk milk, sugar, and flour together in a large bowl. Add eggs, vanilla extract, thyme leaves, black pepper, and salt; whisk until batter is smooth.
Spread blackberries and peach slices out in the prepared casserole dish. Pour batter over the top.
Sesli anlatım, porsiyon ayarı ve daha fazlası