Gather ingredients.

Add pepperoncini peppers and liquid, onion soup mix, and ranch dressing mix to a large ziplock plastic bag; seal bag, and massage until seasonings are dissolved, about 15 seconds. Add chicken cutlets; seal bag, and massage until well coated. Store in refrigerator, laying flat, at least 30 minutes or up to 24 hours.

Preheat grill to medium-high (400°F to 450°F). While grill preheats, let chicken cutlets stand at room temperature. Remove chicken cutlets and pepperoncini peppers from marinade; discard marinade and set aside pepperoncini peppers. Place chicken cutlets on oiled grates; grill, covered, until a thermometer inserted into thickest portion of chicken cutlet registers 165°F, 3 to 5 minutes per side. (During last minute of cook time, place a provolone slice on each chicken cutlet.)

Remove chicken cutlets with melted provolone from grill, and place on a baking sheet; cover loosely with aluminum foil, and let rest 5 minutes.

Meanwhile, place buns, cut sides down, and reserved pepperoncini peppers on oiled grates; grill, uncovered, turning pepperoncini peppers, as needed, until charred and a thermometer inserted into pepperoncini peppers registers 165°F and bread is toasted, 1 to 2 minutes for buns and about 3 minutes for pepperoncini peppers.

Remove and discard stems from pepperoncini peppers; thinly slice, and set aside. Spread ranch dressing evenly over cut sides of buns, about 1 tablespoon per bun.

Place 1 cutlet on each bottom bun; top with sliced charred pepperoncini peppers (about 2 teaspoons each). Garnish with parsley, and top with top bun. Skewer whole pepperoncini pepper through top bun.