Preheat the oven to 350°F with a rack in the center position. Line a rimmed sheet pan with parchment paper.
In a large bowl, combine ⅓ cup of the chimichurri sauce with the bread crumbs until there are no dry clumps. Add the ground beef, pork, eggs, and salt. Mix well, then with wet hands, form golf ball-size meatballs (about 2 tablespoons each) and place on the prepared sheet pan. You should have about 30 meatballs.
Bake for 15 minutes. Turn the oven to broil and broil for about 5 more minutes, or until the meatballs are browned and the internal temperature reaches 165°F on an instant-read thermometer.
Serve with the remaining chimichurri sauce on the side.