1pound small button mushrooms, trimmed but left whole
1 tablespoon chopped garlic
Instructions
Put the oil in a large skillet over medium heat. When it’s hot, add the chicken and sprinkle with salt and pepper. Adjust the heat so it sizzles without burning, and cook, undisturbed, until it’s browned and releases easily from the pan, 5 to 8 minutes.
Meanwhile, make the sauce. Put the tomato paste and vinegar in a medium bowl. Add 1 1/2 cups water, the sage, red chile flakes, and a sprinkle of salt and pepper. Whisk with a fork until smooth.
Turn the chicken when it’s browned on one side and releases easily, after about 5 minutes. Scatter the mushrooms and garlic onto the hot fat. Pour the sauce over the chicken and vegetables, then shake the pan once or twice to combine. Bring the mixture to a boil, then reduce the heat so it bubbles steadily without splattering. Cook uncovered, carefully shaking the pan a couple times more, until the chicken is just separating from the bone, about 20 minutes. Taste and adjust the seasoning, and serve.