To a large frying pan on medium-high heat, add the olive oil and butter. Once hot, and almost smoking, add the mushrooms to the pan in one even layer. Wait for 1-1.5 minutes for the mushrooms to brown on the bottom, then flip them over to brown the other side.
Add the cumin, coriander, sumac, turmeric, cayenne chili, and black pepper. Stir to coat the mushrooms, and cook for an additional 20-30 seconds to toast the spices. Off the heat, season with salt and stir in the lemon juice.
To assemble, spread the hummus to form a round base on a serving dish. Place the mushrooms in the centre of the hummus, and garnish with the toasted pine nuts, parsley, and a generous drizzle of olive oil.