In a wok, add canola oil and garlic and slowly heat. Eventually, the garlic will start frying. Carefully watch garlic and strain out once the garlic is light brown and crisp. Save the oil. Wipe out wok and bring to high heat. Add 1 tablespoon garlic oil and quickly stir in the spinach. Season and add back the crispy garlic and stir in the vinegar. Check for seasoning.