Put all sauce ingredients except chocolate in a saucepan, mix while bringing to a boil, immediately remove from heat and blend. Strain through a sieve to get a smooth sauce. Heat again, remove from heat, add chocolate chopped into small pieces and stir until melted.
Rinse the spinach, dry it, place in salad bowls or deep plates. Shred the mozzarella by breaking off its individual "layers". Drizzle with heavy cream, arrange on the spinach, lightly sprinkle everything with salt and pepper. Add strawberries cut into pieces and sprinkled with sugar and walnuts browned in a pan and chopped. Drizzle with chocolate sauce.
