In a shallow bowl or large resealable bag, whisk together 2 tbs olive oil, 2 tbs lemon juice, 2 tsp minced garlic, 1 tsp dijon mustard, 1 tsp dried oregano, 1 tsp salt, and 1/2 tsp black pepper until combined.

Marinate the chicken

Trim any excess fat from the 2 chicken breasts and flatten to even thickness (about 1/2 inch) with a meat mallet or rolling pin. Add the chicken to the marinade, coat thoroughly, and refrigerate for at least 20 minutes and up to 2 hours. If short on time, 20–30 minutes is sufficient.

Grill the Chicken

Preheat a grill or grill pan over medium-high heat (about 400°F / 200°C). Brush the grill grates or pan with a little oil to prevent sticking. Remove chicken from marinade, letting excess drip off. Grill chicken 5–7 minutes per side, until internal temperature reaches 165°F (74°C) and juices run clear. Transfer to a cutting board and let rest 5 minutes.

Slice the rested chicken thinly against the grain into strips or bite-sized pieces.

Dressing

In a small bowl or jar, combine 3 tbs olive oil, 2 tbs red wine vinegar, 1 tsp honey or maple syrup, 1 tsp dijon mustard, 1/2 tsp salt and 1/4 tsp black pepper. Whisk or shake vigorously until emulsified. Taste and adjust seasoning or acidity as desired.

Salad Assembly

Place 6 cups mixed salad greens in a large bowl or divide between two plates.

Add 1 cup halved cherry tomatoes, 1 cup sliced cucumber, 1/4 cup thinly sliced red onion, and 1 sliced avocado over the greens.

Drizzle about half of the dressing over the salad and gently toss to coat the ingredients evenly. Add more dressing as needed to taste.

Top the dressed salad with the sliced grilled chicken, sprinkle 1/2 cup crumbled feta and 1/4 cup toasted walnuts or pecans if using.

Serve with lemon wedges on the side for an extra squeeze of fresh lemon juice.