Use a few drops of water to lightly wet the raw sunflower seeds and spread them out on a baking sheet. Sprinkle the spices and salt on the seeds and place in the oven at 325°F oven for ~10 minutes. Let cool.
For the dressing
Whisk together vinegar, green onion, and sugar. Slowly drizzle in olive oil, continuing to whisk. Add salt and pepper to taste.
For the salad
In a bowl, coat the watermelon with lime juice, then combine all the ingredients together in a large bowl. Add dressing as desired (you will probably have dressing left over). Store leftover dressing in a sealed container in the refrigerator.