¼smallred onion, sliced thinly**If the onion is too strong in flavor, soak the slices in ice water for 10 minutes; dry on paper towels before adding to the pasta salad.
Make the creamy salad dressing by combining the mayonnaise, Greek yogurt, white vinegar, buttermilk, chives, parsley, garlic, sea salt, and freshly cracked pepper; whisk until well combined then set aside to allow flavors time to mingle.
Meanwhile, cook the pasta in a large pot of well-salted boiling water until al dente and still a bit firm, per package instructions. Rinse under cold water and drain well. Transfer the pasta to a large mixing bowl to cool completely.
Cook the bacon pieces in a large skillet over medium heat until crispy. Remove from the skillet to a paper towel to drain the grease.
Pour half of the salad dressing over the pasta and toss to coat evenly. Add the bacon, tomato, arugula/spinach, avocado, and red onion; toss to coat evenly, adding more dressing as needed. Season with lots of freshly cracked black pepper, to taste and serve. Enjoy.