Preparation

Preheat the oven to 350 degrees F.

Butterfly the breasts and cover them with plastic wrap.  Pound them thin with a meat mallet until they are about 1/4 inch thick.  The plastic wrap will help not to tear the meat.

Season the inside lightly with salt and pepper and layer them with the one slice of prosciutto, one slice of provolone and 1/4 of the spinach (about 10-12 leaves).  Roll them up using the underside of the breast first, so the what was the top of the breast will remain on the outside (this will result in a cleaner presentation).  Tie them with two of the lengths of butcher twine.  Repeat with the rest of the chicken.  If the skinny end of the chicken does not fit neatly, you can trim it off, or tuck it inside the roll.  

Preheat a large saute pan over medium high heat.  Cover the bottom of the pan with enough oil to coat and sear the roulades on both sides.  This should take about 2 minutes per side.  Place the whole pan in the oven and cook until the internal temperature is 165 degrees F.  This should take 10-12 minutes.