In a large mixing bowl, whisk together the mayonnaise, Dijon mustard, sherry vinegar, garlic powder, dried basil or oregano, kosher salt, freshly ground black pepper, and one tablespoon of the oil from the sun-dried tomato jar. This creamy, tangy base will coat your salad beautifully.

Drain the jar of sun-dried tomatoes and finely chop them into small pieces. You should end up with about one cup. Stir these into the prepared mayo mixture to infuse the sauce with their rich, sweet-tart flavor.

Fold in the shredded cooked chicken, grated Parmesan cheese, and finely chopped shallot. Mix until everything is well coated and combined. The chicken should be fully enveloped in that luscious, flavorful dressing.

Taste your salad and adjust the seasoning with additional salt or pepper as needed. If you're using fresh basil, chop it or leave the leaves whole, then sprinkle it on top for a pop of color and freshness.

Refrigerate any leftovers in an airtight container for up to five days. Enjoy it cold or let it sit at room temperature for a few minutes before serving.