Soak the beans overnight in plenty of fresh filtered water, or for at least 8 hours. Drain and rinse well. Place in a cooking pot with more water, bring to a boil, reduce to simmer, and cook covered for about 45 minutes until the beans are tender. Add one teaspoon of the salt towards the end of cooking, then turn off the heat and let the beans sit in the salty water until you’r ready to use them (this can be a few days ahead).
Heat a knob of oil in a large stockpot. Slice onions and add to the pot with about half a teaspoon of the sea salt, stir well to coat and cook for about 7-10 minutes until the onions are lightly golden and silky. Add the garlic and cook for two minutes. Add the fennel, smoked paprika, thyme, bay, crushed chilli flakes, and black pepper, stir well to coat. Cook for 10-15 minutes, stirring often, until the fennel is tender. If the pot become too dry at any point, add a touch of broth.
Add tomato paste and let cook for 2 minutes, then add the broth, crushed tomatoes, and the slices of lemon. Drain the beans and add to the pot. Bring to a boil, reduce to simmer and cook or 20-45 minutes until the flavours have developed to your liking. Add the honey, stir, taste and adjust seasoning if desired.
In a dry skillet over medium heat, toast the fennel seeds until fragrant. Remove from heat and grind a few in a mortar and pestle, or with the back of a spoon. Set aside for garnish.
Just before serving, add the kale and stir well to combine. Remove from heat and let the residual warmth wilt the greens.
Ladle the stew into bowls, drizzle generously with olive oil, and top with the toasted fennel seeds. Say thank you, and enjoy.