Put the nuts in a mixing bowl and set aside. Put the butter into a small saucepan and place over medium heat. As the butter melts, add the thyme leaves, cumin, mustard, cayenne, allspice, and pepper. Allow to simmer for 1 minute. Pour the butter mixture over the nuts, add the salt and toss well to coat. Put the nuts onto a baking sheet in 1 layer. Put the pan into the preheated oven until the nuts are a golden brown, about 20 minutes. Remove and let cool. Serve immediately or keep in a sealed container for 1 week.