Put the mushrooms and walnuts in a medium bowl with the Maggi, 5-spice powder, and ¼ teaspoon each of salt and pepper. Melt the butter (or warm the oil) in a medium saucepan over medium heat. Add the shallots and cook, stirring, for 3 to 5 minutes, until mostly golden. Add the cilantro to the pan and stir to aromatize.
Dump in the mushroom-walnut mixture and stir to combine. Cover, turn the heat to medium-low to facilitate gentle bubbling action, and cook for 8 to 12 minutes, stirring midway, until the mushrooms shrink by about half. Uncover and cook for 1 to 4 minutes more, stirring often, to concentrate the flavor. When no liquid is visible, remove from the heat and let cool for 5 minutes.
Transfer the mixture to a food processor and whirl into a smooth spread. Taste and season with additional Maggi, salt and pepper for a robust, savory, spicy finish. Let the flavors develop about 15 minutes, then serve with crackers.
