Cut <quantity>2</quantity> chicken breasts in half lengthwise, taking care to maintain as equal a thickness as possible throughout

Place the chicken pieces between plastic film or parchment paper. Gently pound each piece with a meat hammer or small heavy bottomed pan. Begin at the thickest end of the cut and work away until a uniform thickness is achieved

Season both sides with salt to taste

Mix <quantity>100<unit>g</unit></quantity> of all-purpose flour, <quantity>2</quantity> beaten eggs, and <quantity>150<unit>g</unit></quantity> of breadcrumbs to bread the chicken pieces. Make sure that they're fully and evenly coated

Preheat the oil to <temperature>175<unit>°C</unit></temperature> in a medium pot over medium heat. Fry the chicken pieces until golden brown and drain them on a wire rack or paper towel

Cover each chicken piece with <quantity>1<unit>tbsp</unit></quantity> of marinara sauce and grated parmesan cheese to taste

Top with mozzarella cheese to taste

Broil it in the oven until the cheese is completely melted

Cut <quantity>4</quantity> pieces of focaccia in half and toast them on a hot skillet drizzled with olive oil. You can add some weight on top to make sure it toasts evenly

Rub <quantity>1</quantity> peeled garlic clove over each slice of focaccia and spread <quantity>½<unit>tbsp</unit></quantity> of marinara sauce

Add the chicken parms and drizzle with more marinara sauce to taste

Add parmesan cheese and basil leaves to taste

Drizzle with extra virgin olive oil to taste and cover with the other slice of focaccia. The chicken parm sandwich is ready

Enjoy!