Grind the fennel seeds with 1 teaspoon salt and 1/2 teaspoon pepper in a spice grinder or chop with a knife. Transfer to a medium bowl; mix with the lemon juice and pork. Add the flour and toss to coat. In another bowl, mix the lemon zest with 2 tablespoons parsley.
Heat a deep skillet or pot over high heat and add the olive oil. Brown the pork in batches, 1 minute per side; transfer to a plate. Add the shallots, fennel bulb, the remaining 3 tablespoons parsley, and salt to taste to the skillet. Reduce the heat and cook until the vegetables are wilted, 2 minutes. Add the tomato paste and cook, stirring, 3 minutes.
Add the mushrooms, wine and 1/2 cup water; scrape up any browned bits. Cover and simmer over low heat until the fennel is tender, 12 minutes. Add the pork and heat through, 2 to 3 minutes. Season with salt and pepper and top with the lemon zest-parsley mixture.