1. If using the Instant Pot method, cut a 2- to 3-pound chuck roast into 3 equal pieces. If using the oven or slow cooker method, leave the roast whole. Season the meat with 1½ teaspoons of coarse sea salt.
2. Cook the roast using one of the three methods below:
a. Oven Method (Cook Time: 5 hours)
b. Preheat the oven to 325°F. Place the seasoned roast in a Dutch oven or other large oven-safe pot with a matching lid along with 2 cups of water. Bake, covered, for 4 to 5 hours, until the meat pulls apart easily with a fork. b. Instant Pot Method (Cook Time: 1 hour, plus time to allow pressure to release)
c. Place the seasoned pieces of roast in an Instant Pot along with ½ cup of water. Seal the lid and press the Meat/Stew button, then press the "+" button until the timer reads 60 minutes. When the timer goes off, allow the pressure to release naturally (meaning, do not manually move the pressure release knob). This should take about 30 minutes; the lid will automatically unlock once the pressure is released.
d. Slow Cooker Method (Cook Time: 4 to 8 hours)
e. Place the seasoned roast in a 6-quart slow cooker with 1 cup of water. Cover and cook on low for 6 to 8 hours or on high for 4 hours, until the meat easily pulls apart.
3. Transfer the cooked beef to a bowl, shred with 2 forks, then set aside.
4. While the beef is cooking, caramelize the onions. melt the butter in a large skillet (cast iron is a good choice) over medium-low heat. Add the onions, season with 1 teaspoon salt, stir, and cook for about 45 minutes, stirring occasionally, until the onions have reduced significantly in size and have developed a deep caramel color. Set aside.
5. Make the polenta: bring the broth and ¾ teaspoon of the salt to a boil over high heat, then reduce the heat to low and whisk in the polenta and let it come back to a simmer. Cover and cook for 10 minutes, then whisk the polenta again, making sure to scrape everything up from the bottom of the plan. Place the lid back on the pan and cook for 15 minutes more, then stir in the butter and pepper, then taste and add up to ½ teaspoon more salt, if desired.
6. Wilt the kale: heat the olive oil in a skillet with a lid over medium heat. Once hot, add the kale and toss it in the olive oil. Place the lid on the pan and allow the kale to wilt, 3 to 4 minutes. Once completely wilted, remove the lid and stir in the lemon juice and salt.
7. Make the red wine reduction: place the red wine, vinegar, salt, and thyme in a medium-sized saucepan over medium-high heat. Bring to a boil, then reduce the heat to medium and simmer for 7 to 10 minutes, until reduced by half. Set aside.
8. Preheat the oven to 350 F, then assemble the casserole. Combine the beef and red wine reduction and toss to coat, then spread the polenta in the bottom of a 3-quart casserole dish. Next, layer the kale over the top of the polenta, then spread the beef over the kale, and top with the caramelized onions.
9. Bake for 30 minutes, until the beef is slightly browned and the casserole is fully warmed through. Garnish with fresh parsley, let cool slightly, and serve!