Tuscan Bean Stew

It may be a little premature for me to post this recipe because I've only made it once. When I made it I didn't want to wait to soak the beans and cook them, so I used two cans of white kidney beans instead, and it was delicious. This means I don't know which version is better - with the dry beans or the canned beans or if they're both just as good as the other. Thanks Cook's Illustrated for the base recipe!

Part 1 - the beans

Salt

1 lb dried cannellini beans (about 2 cups), rinsed and picked over (OR two cans canned beans)

Part 2 - the mushrooms
1⁄2 oz dried porcini mushrooms
1⁄2 cup water (save to add to the soup)

Part 3 - stage 1 of the soup
1 Tbsp extra virgin olive oil plus extra for drizzling
1 large onion, chopped
2 ribs celery, cut into 1⁄2" pieces
2 carrots, in 1⁄2" pieces
8 garlic cloves, crushed
4 cups water
3 cups broth
2 bay leaves

Part 4 - stage 2 of the soup
14oz (398mL) can diced tomatoes
1 medium bunch kale or collard greens (about 1 pound), stems trimmed, leaves chopped into 1-inch pieces)
1 sprig fresh rosemary

Part 5 - serving
Ground black pepper
Grated Parmesan cheese

1. Dissolve 3 tablespoons salt in 4 quarts cold water in large bowl or container. Add beans and soak, at room temperature, for at least 8 and up to 24 hours. (Soaking the beans in salt water overnight helps them cook up creamy, with tender skins.) Drain and rinse well.
2. Adjust oven rack to lower-middle position and heat oven to 250°F. (Cooking the beans at a near-simmer in a 250°F oven leads to fewer exploded beans in the finished stew.)
3. Pour 1⁄2 cup boiling water in a small bowl and add dried mushrooms. Let stand until mushrooms soften, about 5 minutes. Lift mushrooms from liquid with fork and mince. Strain liquid through fine-mesh strainer lined with paper towels into medium bowl. Set mushrooms and liquid aside.
4. Heat oil in large Dutch oven over medium heat until shimmering. Add onion, celery, and carrots. Cook, stirring occasionally, until vegetables are softened and lightly browned, 10 to 16 minutes. Stir in garlic and cook until fragrant, about 1 minute. Stir in remaining 4 cups water, broth, bay leaves, soaked beans, and reserved mushrooms and cooking liquid. Increase heat to high and bring stew to simmer. Cover pot, transfer to oven, and cook until beans are almost tender (very centre of beans will still be firm), 45 minutes to 1 hour.
5. Remove pot from oven and stir in tomatoes and greens (the acid in tomatoes can interfere with the beans’ tender texture. Add them toward the end of cooking, after the beans have already softened). Return pot to oven and continue to cook until beans and greens are fully tender, 30 to 40 minutes longer.
6. Remove pot from oven and submerge rosemary sprig in stew. Cover and let stand 15 minutes. Discard bay leaves and rosemary sprig; season stew with salt and pepper to taste. If desired, use back of spoon to press some beans against side of pot to thicken stew. Serve, sprinkled with Parmesan cheese and lightly drizzled with olive oil.