In a very large skillet cook sausage over medium-high heat about 8 minutes or until browned, turning once. Remove from skillet, reserving any drippings. Cut sausage into 2-inch pieces (sausage will not be cooked through). Set sausage aside.
In the same skillet cook onion and garlic in reserved drippings about 3 minutes or until tender (add olive or cooking oil to skillet, if necessary). Carefully add broth and lemon juice. Add salt, marjoram, and ground black pepper. Return sausage to skillet. Bring to boiling; reduce heat. Cover and simmer 15 minutes. Add sweet peppers; simmer, covered, 10 minutes more or until an instant-read thermometer inserted in the sausages registers 160 degrees F.
Meanwhile, in a 4-quart Dutch oven, bring a small amount of salted water to boiling. Add spinach. Cook, covered, until just wilted, about 30 seconds. Drain spinach; transfer to a bowl. Stir in vinegar. Set aside.
Using a slotted spoon transfer sausage mixture to one half of a serving platter. Spoon Creamy Polenta onto the other half; cover to keep warm. In a screw-top jar combine 1/3 cup water and the flour; cover and shake well. Whisk into cooking liquid in skillet. Cook and stir until thickened and bubbly; cook and stir 1 minute more. Spoon some of the sauce over Creamy Polenta and sausage mixture. Top sausage mixture with spinach. Pass remaining sauce. Makes 6 main-dish servings.
In a saucepan bring 2-1/2 cups of the water to boiling. Meanwhile, in a bowl combine yellow cornmeal, remaining water (cold), and salt. Slowly add cornmeal mixture to boiling water, stirring constantly. Cook and stir until mixture returns to boiling. Reduce heat to low. Cook, covered, until mixture is thickened, stirring occasionally. Before serving, stir in milk until mixture is creamy. Gently stir in purchased dried tomato tapenade or basil pesto, swirling with a spoon or spatula to achieve a marbled appearance.