the original post has some suggestions as well but has been closed - you can search for it. Additionally here are few options right off the highway organized from South to North
Trattoria La Casareccia
235 Reviews
Rated #1 of 36 Restaurants in Ceccano
$Italian, Vegetarian Friendly, Vegan Options
Via Marittima 182 | S. Svia Dei Monti Lepini Vicino Alla Viscolube, 03023 Ceccano, Italy
+39 0775 640590
Mon – Fri 7:00 PM - 12:00 AM Mon – Sat 10:30 AM - 4:00 PM
Locanda Di Bacco
770 Reviews
1 of 97 Restaurants in Monterotondo
$$ - $$$Italian, Barbecue,
Contemporary
Piazza della Liberta' 9, 00015, Monterotondo, Italy
+39 06 9062 2366 Wed – Sun 12:45 PM - 2:30 PM 5:30 PM - 10:45 PM
Le Primare
505 Reviews
1 of 5 Restaurants in Ponzano Romano
$Italian, Mediterranean, Vegetarian Friendly
Localita Primare | Via Della Mola, 607, 00060 Ponzano Romano, Italy
+39 380 359 1308 Tue – Sun 12:00 PM - 3:00 PM Fri – Sun 7:30 PM - 10:00 PM
Il Caminetto
292 Reviews
2 of 30 Restaurants in Orte
$$ - $$$Italian, Mediterranean
Corso Garibaldi 90, 01028, Orte, Italy
+39 348 789 2449 Tue – Sun 12:30 PM - 2:30 PM 7:30 PM - 10:30 PM