Melt the butter over medium heat in a large sauté pan. Continue cooking until it turns a light golden brown, keeping a vigilant eye on it. Stir in the walnuts and cook for 1 minute. Add the poppy seeds and garam masala and cook for 1 minutes. Stir the honey and vinegar into the nuts and seed. Increase the heat to medium-high and whisk the pasta water into the butter for about 2 minutes, or until the sauce begins to thicken.
Toss with pasta and serve immediately.