In a large saucepan heat oil over medium-high heat. Add onions, fry until slightly soft and translucent then add garlic, stir, and continue to fry another minute stirring until garlic is golden brown. Carefully spoon out onion and garlic with a slotted spoon to a baking sheet. Add peanuts, stirring often. Fry until peanuts are golden brown. Remove and place on baking sheet. Add chipotle chiles, ancho chiles and chile de arbol, fry until soft, puffed and slightly darkened, about one minute, stirring often. Finally, add sesame seeds, fry for 30 seconds, and remove pan from heat. Carefully spoon chiles and sesame seeds to baking sheet. Allow oil to cool slightly before returning to blender to finish making salsa macha.
Place onions, garlic, peanuts, chiles and sesame seeds in blender or food processor along with vinegar, salt, pepper, oregano, brown sugar, and water. Pulse to coarsely chop, with blender or food processor on low carefully add oil and blend until smooth, but if salsa remains thick and chunky, adjust speed as needed to blend. Taste, adjust seasoning if needed. Pour salsa into container. Drizzle over steak.