Dilute 10 g of gelatin in a small amount of cool water and leave it for 15-30 minutes before swelling (the exact time is given on the gelatin package). Grind 100 g of watermelon pulp (puree) in a blender. Then put the milk on the stove, bring to a boil, remove from the stove. In hot, slightly cooled milk, we dissolve the swollen gelatin, add chopped watermelon, condensed milk and stir until smooth. Strain the mixture through a fine sieve. Pour the mixture into molds and put in the refrigerator until gelatin has set for 1.5-2 hours. Dilute 10 g of gelatin in a small amount of cool water and leave to swell. Grind the remaining 100 g of watermelon pulp (puree) in a blender. We put the swollen gelatin in a water bath and heat it up to a liquid state (gelatin cannot be boiled!). Combine gelatin, watermelon puree and 20 grams of sugar. Filter the mixture through a fine sieve. We take our molds with the first layer of panna cotta from the refrigerator and carefully pour the watermelon mixture on top and put in the refrigerator until it completely hardens. We set all night.