Bring water and salt to a boil in a large saucepan; pour polenta slowly into boiling water, whisking constantly until all polenta is stirred in and there are no lumps.
Reduce heat to low and simmer, whisking often, until polenta starts to thicken, about 5 minutes. Polenta mixture should still be slightly loose. Cover and cook for 30 to 40 minutes, whisking every 5 to 6 minutes. When polenta is too thick to whisk, stir with a wooden spoon. Polenta is done when texture is creamy and the individual grains are tender.
Turn off heat and gently stir 2 tablespoons butter into polenta until butter partially melts. Cover and let stand 5 minutes to thicken; stir and taste for salt before transferring to a serving bowl. Top polenta with remaining 1 tablespoon butter.
*For creamier polenta, substitute water with milk. For more savory polenta, substitute water with chicken stock.
Place a large Dutch oven over high heat with 2 tablespoons canola oil.
Cut the beef into 2-inch thick pieces and season with 1 teaspoon salt. Put the flour in a large shallow dish. Working in batches, dredge the beef in the flour and sear in the Dutch oven until dark brown on all sides, about 4 minutes per side. Reserve seared beef on a large plate.
After all the beef is seared, reduce the heat to low. Add the tomato sauce and red wine to the pot and scrape up any brown bits that may have accumulated. Add the garlic, basil, parsley, paprika, and cayenne pepper. Sauté until fragrant, about 2 minutes. Add the beef stock and bring to a simmer. Continue to cook until reduced and thickened slightly, about 20 minutes.
Reduce heat to low and return the seared beef to the pot. Cover and cook 2 hours. Add the potatoes, carrots, and onion. Continue to cook until the meat and vegetables are very tender, about 1 1/2 additional hours. Add the lemon zest and lemon juice and stir to incorporate.
Serve warm over polenta and garnish with parsley.
Servings 6