Marinate the chicken in buttermilk for at least 30 minutes.
Combine flour, garlic powder, paprika, salt, and pepper in a shallow dish.
Heat oil in a large skillet over medium-high heat.
Remove chicken from buttermilk and dredge in the flour mixture, shaking off excess.
Fry the chicken for about 5-7 minutes on each side, or until golden brown and cooked through.
Once cooked, transfer the chicken to a plate lined with paper towels to drain excess oil.
While the chicken rests, prepare the salad by combining mixed greens, cherry tomatoes, cucumber, and red onion in a large bowl.
In a small bowl, whisk together olive oil, red wine vinegar, Dijon mustard, salt, and pepper.
Slice the rested chicken and layer it on top of the prepared salad.
Drizzle with dressing and serve immediately.