Heat oven to 375 degrees. Toss kale leaves with a light drizzle of olive oil and pinch of pepper. Spread in single layer on sheet pan and bake 5-7 min, until crisp on edges. Set aside.
In large skillet, cook and crumble sausage in 1 T olive oil until just barely done. Using a slotted spoon, remove from pan and set aside (to add to simmering sauce and finish cooking later).
In the same pan with sausage juices, add 2 T olive oil and sauté fennel, fresh tomato, onion and carrot until softened, approx. 5 min. Add garlic and cook 1 min more. Add diced and crushed canned tomatoes and bring to a simmer; cook until fennel is completely softened, approx. 20 min, adding more water as needed for desired consistency. Add sausage and simmer for 3 min.
Boil gnocchi in lightly salted water until floating and tender, according to package directions (times vary). Drain, drizzle with 1 T of olive oil and gently toss; add to sauce while hot. Toss all with kale and herbs, then garnish with cheese and fennel fronds, as desired. Serve immediately.