If you're looking for new lunch ideas, you've found one! Plus this recipe uses leftovers from our 

Pesto Chicken and Sweet Potatoes with Whipped Feta recipe

Basil Pesto Chicken Sandwich

Line a large rimmed baking pan with foil. Lightly spray foil with nonstick spray; set aside.

Stir together 1/2 jar pesto and 1 tablespoon mayonnaise in a small bowl. Pat chicken dry with paper towels. Brush chicken thighs and onion wedges with pesto mixture to coat; place in prepared baking pan.

Roast for 20 to 25 minutes or chicken reaches 165 degrees. Remove from oven; cool. Slice chicken into strips.

Stir together remaining 1/2 cup mayonnaise and 2 tablespoons pesto. Spread on toasted bread. Top 4 toast slices. Top with roasted pesto chicken thighs and roasted onions, cherry tomatoes, and baby arugula. Sandwich with remaining toasted bread slices, pesto side down.