2 cups warm milk
1 1⁄4-oz. package active dry yeast
1 tbsp. sugar
1 tbsp. plus 2 1⁄2 cups sour cream
3⁄4 cup plus 3 tbsp. margarine, softened
Freshly ground black pepper
1. Stir together 3⁄4 cup flour, 1⁄2 cup milk, yeast, and sugar in a large bowl to make a loose dough. Cover with a towel; let rise in a warm spot until doubled in size, 1–1 1⁄2 hours.
2. Whisk together remaining milk, 1 tbsp. sour cream, and 1 1⁄2 tsp. salt in a medium bowl; add mixture to risen dough. Add remaining flour and 2 tbsp. of the margarine and mix. Turn dough out onto a lightly floured surface; knead until soft and smooth, 10–12 minutes. Shape dough into a ball, dust with flour, and transfer to a large bowl. Cover with a towel; let rise in a warm spot until doubled in size, about 1 1⁄2 hours.
3. Preheat oven to 450°. Grease a 9" × 13" pan with 1 tbsp. of the margarine. Divide dough into 24 equal pieces; roll each into a 10"-long rope. Tie each rope into a knot. (Keep dough ropes covered with a towel while working.) Arrange knots in pan in a single layer. Cover with a towel and let rise in a warm spot until about one-third larger, 40–45 minutes. Brush knots with 4 tbsp. margarine (melted) and bake until golden brown, about 15 minutes. Reduce heat to 350°; bake until cooked through and deep golden brown, about 5 minutes more.
4. Heat remaining margarine in a medium saucepan over medium heat. Stir in remaining sour cream and season with salt and pepper to taste. Cook, stirring constantly, until just hot, about 3 minutes. Remove from heat. Using tongs, separate knots while still hot and dip in sour cream sauce to coat; transfer to a large platter. Pour any leftover sauce over knots, cover loosely with a towel, and let soften for 10 minutes. Eat warm.
MAKES 2 DOZEN