Preheat your oven to 400°F (200°C). Spread the pecans onto a baking sheet and toast them for 8–10 minutes until golden and fragrant.

In a large mixing bowl, combine ½ cup mayonnaise, ½ cup Greek yogurt, 2 tablespoons Dijon mustard, 1 tablespoon stone-ground mustard, and 1 tablespoon lemon juice. Whisk until smooth.

Fold in 2 cups of diced cooked chicken, 1 cup of halved red grapes, 1 chopped Granny Smith apple, ¼ cup of finely chopped red onion, and toasted pecans into the chicken salad base.

Slice each croissant in half horizontally. Optionally toast the cut sides in the oven for 3-5 minutes.

Generously spoon the chicken salad mixture into the bottom half of each croissant. Place the top half back on and press down gently.

Serve the sandwiches immediately with a fresh salad or fruit.