Finely dice the onions and garlic. Pluck the thyme leaves from the stems. Heat the oil in a pan. Gently fry the ground met until it is light brown. Add the onions, garlic and thyme and fry them with the meat for 2 minutes. Stir in the tomato puree and briefly fry it with the other ingredients. Pour in 1 1/4 cup of water and bring this to a boil. Mix in half of the cranberries. Season the ground meat mixture with salt, pepper and cinnamon.
Cut the pumpkin into two halves, and scoop out he soft fruit flesh and seeds from the pumpkin with a spoon. Grate the fruit flesh with the skin. Mix the grated pumpkin with 2 1/2 tablespoons of butter and the remaining cranberries, and season with salt and pepper. Grease four small casserole dishes (approx. 4 3/4 inch diameter) with 1/2 tablespoon of butter. Fill them with the ground meat mixture and spread the pumpkin over this. Bake in a preheated oven at 400 degrees Fahrenheit in the bottom third of the oven for 45 minutes. Serve the cranberry ground meat casserole with sour cream.