Charred Cabbage With Sausages and Apples

Name: Charred Cabbage With Sausages and Apples
Ingredients: 1 small head of cabbage (about 1½ lb.), quartered through stem end, cored; ¼ cup plus 2 Tbsp. extra-virgin olive oil; 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, plus more; 1–1½ lb. sweet Italian sausage links; Zest and juice of 1 lemon; 2 garlic cloves, finely grated; ½ cup sour cream; ⅓ cup drained prepared horseradish (such as Inglehoffer); ½ small Honeycrisp apple, cored, thinly sliced; 1 small shallot, thinly sliced lengthwise; Coarsely chopped dill (for serving); Flaky sea salt; Freshly ground pepper