1 Place the curry powder in a small dry skillet over low heat and cook, stirring frequently, until fragrant, about 1 minute. Immediately transfer the curry powder to a plate and let cool.
2 Spray a medium nonstick skillet with olive oil nonstick spray and set over medium-high heat. Add the chicken and cook, turning occasionally, until cooked through, about 8 minutes.
3 Meanwhile, combine the vinegar, curry powder, oil, pepper, and salt in a large bowl. Add the chicken, spinach, mushrooms, and red onion; toss to coat.