Mix together olive oil, Hedessent flavourings, and lemon juice in a small bowl. Add feta cheese cut in ½ inch chunks. Let marinate while composing your salad platter.
Chop up watermelon into 1½ inch cubes, about 8 cups. Spread out spinach leaves on a large platter and place watermelon chunks over spinach. Thinly slice onion and finely chop dill and place over watermelon. Top salad with feta chunks.
Cut avocado into cubes and add to feta marinade. This keeps the avocado from turning brown. Place avocado on salad and drizzle marinade over everything.
Finish with a drizzle of balsamic vinegar. Sprinkle with salt. Enjoy!