Place garlic cloves and oil in a small heavy-bottomed saucepan. Cook over medium-high until oil around garlic begins to bubble, 1 to 2 minutes. Reduce heat to low; cook, stirring often and flipping cloves occasionally, until golden brown and soft, about 20 minutes. Remove from heat. Transfer 6 of the garlic cloves to a small bowl and mash with a fork; reserve oil and remaining 6 whole garlic cloves in saucepan.

Heat a large Dutch oven over medium. Add pancetta and cook, stirring occasionally, until browned and crispy, about 6 minutes. Using a slotted spoon, transfer cooked pancetta to a small bowl, reserving 1 tablespoon drippings in Dutch oven; discard remaining fat.

Add bay leaves to Dutch oven; cook over medium until fragrant, about 30 seconds. Stir in leeks, celery, carrots, and salt; cook, stirring occasionally, until leeks are lightly browned and tender, about 4 minutes.

Drain 1 can of the beans; transfer beans to a medium bowl. Mash beans using a fork. Add to Dutch oven along with remaining 2 cans undrained beans, chicken broth, Italian seasoning, black pepper, and crushed red pepper. Bring to a boil over high, stirring occasionally. Reduce heat to medium; cook until carrots are tender and soup thickens, about 10 minutes.

Stir in kale, mashed garlic, and 1/4 cup cooked pancetta; cover and cook until kale is wilted, about 2 minutes. Add cream, stirring to combine; cook until cream is heated through, about 1 minute. Remove from heat and divide soup among 6 bowls; top each with about 2 teaspoons pancetta and 1 cooked garlic clove. Drizzle evenly with reserved garlic oil. Serve with grated Pecorino Romano cheese and toasted bread.