Toast the beef strips with paprika powder, ground coffee, a pinch of salt and pepper. Set aside for 15 minutes.
Heat 3 tablespoon oil in a large skillet over medium heat, add the beef strips and increase the heat to medium-high. Fry the beef in batches until browned on each sides. Remove beef to the bowl, and set aside.
In the same pan, add the onions. Cook the onions in a medium heat until soft, or about 3 minutes. Remove the onion to the same bowl of beef, and set aside.
Melt 2 tablespoon of butter in a same pan. Add the mushrooms and cook in a medium-high heat until browned, and cook through. Stirring occasionally, add chopped garlic and thyme while cooking.
Reduce the heat, add tomato paste, beef, and shallots. Cook for about 1-2 minutes, and deglaze a pan with brown stock, cook until the stock simmering, Fold in the yogurt. Taste and adjust the seasoning with salt and pepper.