Russian Cabbage Rolls with Gravy Recipe

Ingredients

• 1 medium head cabbage
• 2.5 cups water, divided
• 0.75 cup uncooked white rice
• 3 tablespoons vegetable oil, divided
• 2 onions, chopped, divided
• 1 pound ground beef
• 0.75 pound ground pork
• salt and ground black pepper to taste
• 3 carrots, grated
• 3 tablespoons tomato paste
• 2 tablespoons sour cream
• 1 teaspoon dried mixed herbs, or as needed