Heat the oil in a 12-inch skillet over medium-high heat. Add the chicken and cook for 10 minutes or until it's well browned on both sides. Remove the chicken from the skillet. Reduce the heat to medium. Add the garlic to the skillet and cook and stir for 1 minute. Stir in the vinegar and cook, scraping up the browned bits from the bottom of the pan. Stir the soup and beans in the skillet and heat to a boil. Return the chicken to the skillet. Reduce the heat to medium. Stir in the spinach. Cover and cook until the chicken is cooked through and the spinach is wilted.