Chicken Pesto Sandwich
Ingredients:

2 boneless, skinless chicken breasts
2 tbsp olive oil (for grilling)
Salt and pepper, to taste
4 slices of rustic bread (sourdough, ciabatta, or baguette work great)
4 tbsp pesto sauce (homemade or store-bought)
4 slices of mozzarella cheese (fresh or shredded)
1/2 cup arugula or fresh spinach (optional, for freshness)
1 tomato, sliced (optional, for extra juiciness)
1/4 red onion, thinly sliced (optional, for a bit of bite)
1 tbsp balsamic glaze or vinegar (optional, for a sweet tang)
Instructions:
Prepare the Chicken:

Season both sides of the chicken breasts with olive oil, salt, and pepper.
Heat a grill pan or regular skillet over medium-high heat. Grill the chicken for 5-7 minutes on each side, or until fully cooked and the internal temperature reaches 165°F (74°C).
Once cooked, remove the chicken from the pan and let it rest for a few minutes before slicing it thinly.
Toast the Bread:

While the chicken is resting, toast the bread slices in the same skillet or on a grill. You can butter the bread lightly for extra flavor or keep it plain for a healthier option.
Toast until golden and crispy, about 2-3 minutes on each side.
Assemble the Sandwich:

Spread 1 tablespoon of pesto on each slice of toasted bread.
On the bottom slice, layer the sliced grilled chicken, followed by a slice of mozzarella cheese. If you want a melty cheese effect, place the sandwich under a broiler for 1-2 minutes until the cheese is just melted and bubbly.
Add fresh arugula (or spinach), sliced tomato, and red onion for a burst of freshness.
Drizzle a little balsamic glaze or vinegar on top (optional), then close the sandwich with the top slice of bread.
Serve:

Slice the sandwich in half and serve immediately, with a side of chips, fries, or a simple salad.