Romesco Sauce: Place the capsicum/bell pepper halves onto a baking tray and broil until charred and darkended (around 10-20 minutes). Place the charred bell peppers into and bowl and cover with plastic wrap to sweat for 15 minute and then remove the blackened skin.
Add all the ingredients for the sauce into a bender and blend until homogenous. Set aside to let the ingredients marinade.
Breaded chicken: Slice your chicken breast into 2 pieces length-wise. While working with 1 piece at a time, cover the chicken with a piece of plastic wrap and using a meat tenderiser, flatten out the chicken into a thin even piece. Repeat with the other piece. Season the chicken with salt and pepp.
Add your breadcrumbs onto a plate and mix in the parsley, onion powder and garlic powder. Prepare your breading station. Working with 1 piece of chicken at a time, place the chicken into your flour and cover it well. Transfer the chicken to your beaten eggs and cover it well. Transfer the chicken to your seasoned breadcrumbs and press it in well. Repeat with the 2nd piece.
Bring a pot of oil to frying temperature (180C/ 350F). Carefully drop in 1 piece of breaded chicken at a time and fry for 4-6 minutes, depending on the thickness of the chicken and flipping halfway, or until golden brown. Place on a wire rack to drain.
Assemble: On 1 piece of toasted bread, spread on a layer of the homemade Romesco sauce, then top with a piece of chicken. Break a burrata on top of the chicken and top with rocket with a drizzle of olive oil. Close the sandwich. Enjoy!