For the boeuf bourguignon, sauté shallots and meat in batches in a pan with oil. Add garlic and tomato paste and fry briefly.
Transfer everything to the Crock Pot and add spices, herbs, capers, mustard and liquid and mix well. Cook on Low for 8 hours. Add mushrooms and cook on Low for another 1 hour.
Serve the Boeuf Bourguignon with a dollop of sour cream or crème fraiche.