Orecchiette with beef and mushrooms

Serves 3

2 tablespoons extra-virgin olive oil 

1 medium onion, finely chopped 

1 garlic clove, minced 

1/2lb ground beef 

1/2lb mushrooms, chopped

Kosher salt 

Freshly ground black pepper 

½ cup dry white wine 

1 ½ cups chicken stock 

1 teaspoon chopped thyme 

1/2 teaspoon chopped rosemary 

2-3 tablespoons small capers, rinsed 

¾ pound orecchiette 

½ cup Parmigiano-Reggiano cheese, grated 

¼ cup chopped flat-leaf parsley 

2 tablespoons unsalted butter