Drain the lentils, then add them to the pan with the sausage mixture. Stir in the broth, wine, and 1/4 teaspoon pepper. Bring to a boil, then lower the heat and simmer, covered, until the lentils are soft and cooked through but not falling apart, 10 to 12 minutes. Stir in the tomato paste and vinegar. Add the spinach, cover, and cook until the spinach wilts, about 4 minutes. Stir to combine, season to taste with salt and pepper, and serve.