Preheat oven to 225 degrees. Line two baking sheets with parchment paper. For same size shells, draw 8-9 inch circles on the parchment paper and turn the paper upside down.
Beat the egg whites at medium speed until foamy. Add salt and cream of tartar, and beat at medium-high speed until soft peaks form. Add granulated sugar one tablespoon at a time and beat on high speed until stiff peaks form.
With a spoon scoop meringue in the center of the parchment paper following the shape previously outlined. Build up the shells shaping with the back of a spoon so there is a rim higher than the center.
Bake for 50-60 minutes or until the shells are dry to the touch. Turn off the oven and leave the nests in the oven for 2 hours to continue to dry out. Cool on a baking rack.
When shell is completely cool place on a serving plate and add Chocolate Strawberry Greek-Style yogurt in the center. Spread evening. Add assorted fruits to the inner and outer rim of the shell. Sift cocoa over pavlova. Gently cut in slices.
