Avoid instant polenta. Stone-ground grits may be substituted, but the cooking times and texture may be different.
For the fastest polenta, the cornmeal needs to soak overnight.
5 cups water
1 cup dried polenta, preferably stone-ground
1 teaspoon kosher or sea salt, plus more as needed
1/2 teaspoon freshly ground black pepper
450 g rainbow chard
2 tablespoons extra-virgin olive oil, plus more for drizzling
1/2 yellow onion, thinly sliced (1 cup)
4 cloves garlic, sliced
1/2 teaspoon sweet or hot smoked paprika (pimenton)
225 g cremini mushrooms, trimmed and sliced (about 3 cups)
1/2 teaspoon fresh thyme leaves
One can (430g) no-salt-added cannellini beans, rinsed and drained
Combine the water and polenta, cover, and let soak overnight at room temperature.
Transfer the mixture to a medium saucepan over medium-high heat, and stir in 1/2 teaspoon of the salt. Bring to a boil.
Allow it to boil until it starts to spit, then reduce the heat to eliminate the spitting and cook, stirring frequently and scraping the bottom of the pot to prevent sticking, until the polenta thickens and starts to pull away from the sides of the bowl, about 30 minutes. (If you start with unsoaked cornmeal, this will take up to 50 minutes.)
Stir in the black pepper. Taste, and add more salt, as needed. Remove from the heat, but cover to keep warm.
While the polenta is cooking, prepare the chard: Strip the leaves from the stems.
Thinly slice the stems, keeping them separate from the leaves, and coarsely chop the leaves.
Heat 1 tablespoon of the oil in a large skillet over medium heat.
Once the oil shimmers, add the chard stems, onion, garlic and 1/4 teaspoon of the salt and cook, stirring, until they soften, 4 to 6 minutes.
Sprinkle in the smoked paprika and cook just until it becomes fragrant, 30 seconds.
Add the chard leaves and cook just until wilted, 2 to 3 minutes. Taste, and add more salt, as needed. Scoop the mixture into a bowl, cover to keep warm, and rinse out the skillet.
Return the skillet to medium heat. Pour in another 1 tablespoon of the oil; once it shimmers, add the mushrooms and the remaining 1/4 teaspoon salt and cook, stirring, until the mushrooms soften, exude moisture and most of it evaporates, 4 to 5 minutes.
Stir in the thyme and beans and cook just until the beans warm through, 1 to 2 minutes.
Taste, and add more salt, as needed.
To serve, divide the polenta among individual bowls. (If it has set up too much or gotten too firm, whisk in a little more water to loosen.)
Top each portion with the equal helpings of the mushrooms and beans and then the chard mixture. Drizzle with a little oil and serve warm.