Directions Preheat oven to 475 degrees F (245 degrees C).
Heat 1 teaspoon olive oil in a skillet over medium heat; cook and stir pancetta until fat has been released، 3 to 5 minutes. Transfer pancetta to a paper towel-lined plate.
Pour remaining 5 teaspoons olive oil into the same skillet; cook and stir garlic until fragrant، about 20 seconds. Add Brussels sprouts to garlic; cook، stirring constantly، until sprouts begin to brown، 5 to 10 minutes. Transfer sprouts and garlic to a bowl and crumble cooled pancetta over the mixture. Add mozzarella cheese and fennel seed; toss to coat. Place pizza crust onto a baking sheet and spread Brussels sprouts mixture atop pizza crust.
Bake in the preheated oven until cheese is melted and bubbling، about 10 minutes.
Tip Aluminum foil helps keep food moist، ensures it cooks evenly، keeps leftovers fresh، and makes clean-up easy.