Place cardamom, cinnamon stick, cloves, and fenugreek in a small skillet over medium. Cook, stirring, until fragrant, about 1 minute.
Transfer toasted spices to a clean coffee grinder, and pulse until finely ground (or use a mortar and pestle). Stir in the chilli powder; set aside.
Melt butter in a medium saucepan over medium. Add ginger and garlic; cook until fragrant, about 1 minute.
Add reserved spice mixture, tomato paste, cream, and water to saucepan, and cook, whisking constantly, until tomato paste dissolves. Simmer until bubbles form around the edge, about 5 minutes. Whisk in sour cream, Cheddar, and 4 ounces of the Gouda. Cook, stirring often, until cheeses melt and sauce is smooth, about 3 minutes. Stir in 2 teaspoons of the salt. Reduce heat to low, and keep warm.
Meanwhile, bring a large pot of water to a boil, and season with remaining 1/4 cup salt. Add macaroni; cook according to package directions. Drain pasta and return to pot. Add the cheese sauce, and stir well to combine. Transfer mixture to a broiler-safe baking dish.
Preheat broiler. Top pasta mixture with remaining 2 ounces Gouda; broil 3 minutes or until cheese melts.