Cantonese Spiced Pork Meatball Soup

Ingredients

• 2 tablespoons peanut oil
• 1 medium onion
• 1 garlic clove
• 2 quarts beef broth
• 1/2 cup tomato puree
• 1 teaspoon ground allspice
• 1/2 teaspoon grated nutmeg
• 1 1/2 pound ground lean pork
• 1/2 cup long grain rice
• 1 large egg
• 2 tablespoons watercress
• salt