I like to start by pickling the onions so their tangy flavor is ready for the salad. Slice thin, mix with vinegar, a pinch of sugar, and let them sit while preparing the rest.
Whisk together mayonnaise, buttermilk, and sour cream until smooth. Then fold in garlic, dill, parsley, lemon juice, vinegar, salt, and pepper. Chill until serving for a refreshing creamy taste.
Separate the Little Gem leaves, tearing larger leaves in half. Wash thoroughly and spin dry to remove any moisture, which helps the dressing cling to the leaves.
In a large bowl, layer lettuce, cucumber, radishes, avocado, sprouts, pickled onions, and seeds. Gently toss with the chilled Dilly Ranch dressing, adding it gradually to avoid overdressing.