For the Thecha: Roast 6 long green chilies, 5 garlic cloves, 1 tsp cumin seeds, 1 tsp coriander seeds, and ¼ cup peanuts in a little oil until lightly charred. Crush into a coarse paste using a mortar and pestle.
For the Pasta: Cook spaghetti until al dente, reserving some pasta water. Melt 2 tbsp butter in a pan, stir in 2-3 tbsp of the prepared Thecha, then toss in the cooked pasta. Add a splash of pasta water until everything is glossy and well coated.
