Cook ribbon noodles according to package directions until al dente (typically 8-12 minutes). Drain and set aside.
Clean fennel and remove the stalk. Cut fennel, onion, and carrots into cubes of similar size.
Heat a little oil in a large pan over medium-high heat. Add fennel, onion, and carrots, and cook for 5-7 minutes, stirring occasionally, until they begin to soften. Add minced meat, breaking it apart as it cooks, and cook for 3-4 minutes. Add garlic cloves and cook for 1 minute. Season with salt and pepper.
Pour in vegetable stock and simmer over medium heat for 5-10 minutes.
Remove pan from heat. Stir in sauce thickener (follow package directions for the amount), then stir in crème fraîche and fresh parsley. Season to taste.