Heat 1 tablespoon oil in a 12-inch nonstick or well-seasoned skillet over medium heat. Add gnocchi directly from the package and cook for 8 to 10 minutes, turning occasionally, until golden on several faces; transfer to a bowl.
Add remaining oil and chicken sausage and cook for 3 to 4 minutes until browned. Add fennel, salt and pepper and cook for 6 minutes, stirring occasionally.
Stir in garlic for 30 seconds, then add broth. Cover and simmer for 3 to 4 minutes until fennel is tender.
Uncover and add peas and browned gnocchi. Cook for 2 to 3 minutes until peas are hot, gnocchi are tender throughout and most liquid has evaporated.
Remove from the heat and fold in butter, lemon juice and zest. Divide among 4 plates while the gnocchi retain their browned edges.