In a bowl, whisk together the Greek yogurt, mayonnaise, lemon juice, and Dijon mustard until smooth and well combined. Add the black pepper, salt, onion powder, garlic powder, dried parsley, and dried basil, stirring until all spices are evenly distributed and no lumps remain. This creamy herb dressing will anchor the jar and keep the vegetables crisp during storage.

While the dressing rests, hard-boil the eggs if not already done, then chop them into bite-sized pieces. Dice the cucumber into 1/2-inch pieces, halve the cherry tomatoes, thinly slice the scallions, crumble the bacon, crumble the blue cheese, and dice the avocado. Chop the romaine lettuce into bite-sized pieces. I like to prepare the avocado last since it oxidizes quickly—dice it just before layering to keep it bright and creamy.

Divide the dressing from Step 1 evenly between two mason jars or similar containers (about 1/4 cup per jar), spreading it along the bottom. Layer in this order: cucumber, cherry tomatoes, hard-boiled eggs, scallions, blue cheese, and avocado. The layering strategy keeps hearty vegetables on the bottom near the dressing where they won't get soggy, while delicate ingredients stay higher up. Top each jar with the chopped romaine lettuce and crumbled bacon, packing it down gently so the lid closes securely.

Screw the lids tightly onto the jars and refrigerate. When you're ready to eat, simply shake the jar vigorously for 20-30 seconds to distribute the dressing throughout, then pour the contents into a bowl or eat directly from the jar. I find that these jars stay fresh and delicious for up to 3 days when properly sealed, making them perfect for meal prep.