Mix together cornstarch, beef stock, Worcestershire and hot sauce together in a bowl. Stir until smooth.
In a microwave safe bowl, add the vegetable oil, onion, jalapeño, celery, garlic, rosemary, thyme, and Cajun seasoning. Cook until onions are translucent about 8 minutes. Stirring occasionally about every 1-2 minutes of cook time.
Stir into the slow cooker.
Add the meat, mushrooms, and beef stock mixture to the slow cooker and stir.
Salt and pepper to taste.
Cook on low for 6-8 hours until tender.
Serve with rice.