Fry the guanciale in a little fat until translucent. Add the onion and let everything turn golden brown. Add the tomatoes, simmer for about 15 minutes without the lid and season to taste. Optionally add asparagus tips.
In the meantime, cook the orecchiette for 6 to 8 minutes. Drain and add to the sauce. Mix the sauce and orecchiette carefully with 1 tablespoon butter and serve while still warm. Sprinkle generously with parmesan cheese.