Preheat your oven to 200°C (390°F). Line a baking sheet with parchment paper and spread the sliced fennel and cubed sweet potato evenly. Toss with a tablespoon of olive oil, salt, and pepper. Roast for 25-30 minutes until caramelized and fragrant, then remove and let cool slightly.
While the vegetables cool, drain and rinse the chickpeas. In a large mixing bowl, mash the chickpeas with a fork until mostly smooth but with some texture remaining.
Finely chop the roasted fennel and sweet potato, then add them to the mashed chickpeas. Stir in minced garlic, chopped parsley, lemon zest, and half of the olive oil. Mix until well combined.
Gradually add breadcrumbs to the mixture, stirring continuously until the mixture holds together when pressed. If it feels too wet, add a little more breadcrumbs; if too dry, splash in a teaspoon of water or olive oil.
Using your hands, shape the mixture into small balls about 1.5 inches in diameter and place them on the prepared baking sheet, spacing them evenly.
Heat the remaining tablespoon of olive oil in a large skillet over medium heat. Once shimmering, add the veggie balls, cooking in batches if necessary.
Cook the veggie balls for about 8-10 minutes, turning gently with a spatula, until they are golden brown and crispy on all sides. They should crackle softly as they fry and smell nutty.
Remove the veggie balls from the skillet and place on a paper towel-lined plate to drain excess oil. Let them rest for a couple of minutes to firm up.
Serve the veggie balls warm, garnished with additional herbs or a squeeze of lemon if desired. They are perfect on their own or with a dipping sauce.
