1/2 cup (120ml) milk
1 teaspoon (3g) Diamond Crystal kosher salt; for table salt use half as much by volume or the same weight
1 pound (454g) cleaned squid, bodies sliced into 3/4-inch thick rings, tentacles left whole
1 3/4 cups (7 ounces; 200g) all-purpose flour
1/3 cup (1 1/2 ounces; 44g) cornstarch
1/2 teaspoon freshly ground black pepper
1/4 teaspoon baking powder
2 quarts (1.9L) vegetable or other neutral oil
1 recipe Quick and Easy Italian-American Red Sauce in 40 Minutes or Less (see note)
Lemon wedges, for serving