Melt 2 tablespoons of butter in small pan. Saute the onions until translucent and just barely beginning to brown. Add the garlic and saute for another minute. Add the mushrooms and sauté for 5 minutes until the mushrooms release their juices. Add the paprika, dill, salt and pepper. Set aside.

In a Dutch oven, melt 3 tablespoons of butter and stir in the flour, constantly whisking for several minutes until the mixture is a rich, caramelized brown. Add the milk, broth, bouillon cube, and soy sauce, still whisking until the mixture is smooth. Add the mushroom mixture. Bring to a boil, reduce heat to medium, cover and simmer for 15 minutes, stirring occasionally. If the sauce is too thin, allow it to simmer uncovered for a few more minutes to reach desired consistency. If it's too thick, add a little extra milk. Stir in the sour cream and dill and simmer for another 2 minutes. Add salt and pepper to taste.

Serve immediately over pasta with some more fresh chopped dill or parsley as garnish. Add a dollop of sour cream if desired.