Preheat the oven to 350 degrees.
Rinse all of the fresh veggies.
Cut the red bell pepper into slices.
Remove the artichokes from a can and rinse thoroughly. Cut the artichokes in half.
Spray a baking dish with oil spray. Add the red bell pepper slices, shiitake mushrooms, and artichokes to a baking sheet and season with salt and pepper. Bake at 350 degrees for about 1 hour or until the red bell pepper has softened.
Once the veggies are done cooking, place to the side to completely cool for about 30 minutes.
Slice the grape tomatoes in half. Cut the tuna or chicken, feta, and kalamata olives into smaller pieces if necessary.
In a large bowl, add the spring mix greens, grape tomatoes, feta cheese, tuna or chicken, kalamata olives, parsley, and cooked veggies.
Mix the salad in the large bowl. If you plan on serving the whole salad, mix in the dressing. If you only plan on eating a portion of the salad, place a portion of salad on a plate and top with desired amount of Greek salad dressing. Store leftovers in the fridge.