In a bowl, combine the dried porcini mushrooms and hot water. Allow to stand 20 minutes.
Meanwhile, add butter and olive oil to a large skillet. When hot and melted, add the chopped onion, carrots, celery, and fresh mushrooms. Saute until softened. Add garlic. Add the ground beef and the sausages. Stir frequently, breaking up the meats.
Dump all into a crockpot. Add the reconstituted porcini mushroom and also the mushroom soaking liquid, being careful not to add any sand that may be at the bottom of the soaking liquid. Salt and pepper to taste.
Cover crockpot and cook on LO heat for 4-6 hours.
Serve over hot cooked pasta. You may want to top this with shaved Parmesan cheese.