At least 1 hour ahead of time (or overnight) marinate the chicken breasts. Place the thinly sliced chicken breasts in a large plastic bag and with caesar dressing. Refrigerate until ready to cook.
Make the croutons: Preheat the oven to 425F. Cut the bread into small cubes. Place on a sheet pan, drizzle oil, salt, pepper and Italian seasoning on the croutons. Toss so everything is well covered. Bake for 10 mins, toss the croutons to avoid burning, then bake for another 5 minutes. They should be golden brown.
Remove the marinated chicken from the refrigerator 10-15 mins prior to grilling.
Cook tortellini according to package directions. Drain and set aside until the rest of the ingredients are ready. Note: I like to cook al dente so the tortellini don't fall apart in the salad.
While the tortellini is cooking, mix together the caesar dressing until smooth. It should be spoonable/drizzable for the salad - add milk for thinness. Shred the cheese and finely chop the lettuce.
Cook the chicken. Heat a grill pan to medium-high heat and oil if necessary. Once hot, place each chicken breast on the grill pan and cover with a lid (this will help with even cooking and grill marks). Sear for 3-4 minutes on a side, then flip **If the chicken breasts are not pounded/thin, this will take longer. Cook until the internal temperature reaches 165°F. Place cooked chicken on a cutting board to rest for 5-10 minutes. Once cooled, dice chicken into bite-size pieces.
Assemble the salad! In a large bowl, add the chopped lettuce, cooked tortellini, grilled chicken, shredded parm, homemade croutons and drizzle with dressing. Toss so everything is combined! Serve immediately and enjoy!!