Add all the chimichurri ingredients together into the blender. Blitz until combined.
25 g Fresh Parsley, 25 g Fresh Coriander, 3 cloves Garlic, 1 Shallot, 2 Red Chillies, 1 Jalapeno, ¼ cup White Vinegar, ½ cup Olive Oil
Marinating and cooking the chicken
Season the chicken with a generous amount of salt and black pepper.
2 large Chicken Breast, Salt & Black Pepper
Marinate in buttermilk for a few hours or ideally overnight.
½ cup Buttermilk
After the first marinade, discard the buttermilk and then spread half the chimichurri on the chicken. Marinate for another 1-2 hours.
Heat a grill pan over medium-high heat. Grill the chicken for 3-4 minutes on each side until fully cooked. Set aside.
Assembling the sandwich
Spread butter on each side of the halved bread roll. Place the bread onto the same grill pan used for cooking the chicken, turning the heat off, and let it toast from the residual heat.
4 Ciabatta Bread Roll, Butter
Top the bottom half of the toasted bread with 2 tbsp crushed tomatoes.
8 tbsp Crushed Tomatoes
Place a slice of cooked chicken on top and then top with sliced mozzarella cheese.
Mozzarella Cheese
Spread a layer of the remaining chimichurri and, finally, the top half of the bread.
Repeat with the remaining sandwiches.
If using, place the sandwich onto the panini grill.
Notes
Prep time does not include time for marinating the chicken.
If you don't have buttermilk, simply mix together 1 cup of milk and 1 tbsp lemon juice. Leave to sit for 5 minutes until tiny curdles form.
For the chimichurri, ideally, you should use both coriander and parsley. However, you can use only either one in this recipe. Simply double the amount so that the total amount of herbs adds up to 50g.
You can make the chimichurri ahead of time. Simply store it in an airtight jar and keep refrigerated for up to 2 weeks. Or you can also freeze it in the freezer for up to 3 months.
If freezing the chimichurri, make sure you leave some space at the top of the jar as the sauce may expand. Defrost in the fridge overnight before use.