To make this salad, start by preparing the dressing. Add the dressing ingredients (the olive oil, shallots, garlic, dijon mustard, lemon, kosher salt, and ground black pepper) to a small bowl and whisk until fully combined.
Taste and adjust the seasonings as needed, then set the dressing aside and prepare the rest of the salad.
Next, wash and chop the radicchio, kale, and romaine, and transfer them to a large bowl.
Then, cut the avocado and add it to the bowl alongside the sunflower seeds.
Peel, segment, and chop the orange and grapefruit and add them to the salad bowl
Finally, pour in the dressing and toss to fully combine.
Once the salad is tossed, taste and adjust the seasonings as needed. Then, serve and enjoy!