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