Rinse the arugula under cold water and pat dry.
In a large bowl, add the fresh arugula.
Slice the avocado and arrange it on top of the arugula.
Thinly slice the radishes and sprinkle them over the salad.
Add the sunflower seeds to the bowl.
Crumble feta cheese on top of the salad.
In a small bowl, whisk together olive oil and balsamic vinegar.
Drizzle the dressing over the salad.
Season with salt and pepper to taste.
Toss gently to combine all ingredients.