How to Make It
Heat 2 tablespoons oil in a straight-sided 14-inch skillet over medium-high. Add sausages; cook, turning occasionally, until browned on all sides, about 5 minutes. Transfer sausages to a plate. Add fennel wedges, cut sides down, to skillet; cook until browned on both sides, about 2 minutes and 30 seconds per side. Transfer to plate with sausages.
Add fennel seeds, peppercorns, and remaining 2 tablespoons oil to skillet; cook over medium-high, stirring constantly, until toasted and fragrant, 30 seconds to 1 minute. Remove half of the spice mixture from skillet, and reserve for garnish.
Add stock to skillet, stirring and scraping bottom of skillet to loosen browned bits. Bring to a simmer over medium-high. Return sausages and fennel wedges to skillet; cover and reduce heat to low. Cook until fennel wedges are tender, about 30 minutes. Sprinkle with salt.
Spread hummus smoothly on a platter. Top with sausages and fennel wedges; spoon sauce from skillet over platter. Garnish with lemon zest, lemon wedges, reserved fennel fronds, and reserved spice mixture.