Heat a large pan medium-high and add the butter.
When the butter is melted and bubbly, fry the cubed sourdough until golden. Sprinkle with sea salt and oregano. Allow to cool.
Mix yogurt, garlic, lemon juice, Worcestershire sauce, 20 grams Parmesan cheese, olive oil, maple syrup, and Dijon mustard in a mini food processor to make the dressing. You may need to add a bit of water if the dressing is too thick.
Add sea salt and pepper to taste.
Cook the pasta according to the package directions. Allow to cool.
Cube the chicken and avocado into bite-sized pieces.
Assemble the salad in a large bowl or platter. Add pasta, chopped romaine, croutons (save some for serving), chicken, avocado, and the chopped fresh basil.
Pour the dressing over the salad and toss everything together.
Top with the remaining croutons and Parmesan (grated into shards).
Serve.