1 Tablespoon olive oil
1 large fennel bulb, halved through core, thinly sliced lengthwise, fronds chopped
1 pound spicy Italian sausages, casings removed, sausage coarsely crumbled
One 8-ounce package sliced fresh baby bella mushrooms
4 large garlic cloves, minced
1 Tablespoon fennel seeds, coarsely crushed
1/2 cup heavy cream
1 cup chicken broth
One 16-ounce fresh tortellini with 3-cheese filling
One 5-ounce package fresh baby spinach leaves
1/2 cup finely grated Parmesan cheese plus additional, for serving
Heat oil in large nonstick skillet over medium-high heat. Add sliced fennel bulb, sausage, and mushrooms; sauté until sausage is brown and cooked through and fennel is almost tender, 12 to 15 minutes. Add garlic and fennel seeds; stir 1 minute. Stir in cream, then 1 cup broth; boil until liquid is reduced and very slightly thickened, 2 to 3 minutes.
Meanwhile, cook tortellini in large pot of boiling salted water until just tender but still firm to bite, stirring occasionally. Drain tortellini; return to same pot.
Add sausage mixture to tortellini in pot. Toss over medium heat until blended. Add spinach; toss gently until spinach wilts. Stir in 1/2 cup cheese; add more broth by 1/4 cupfuls to moisten if dry. Season with salt and pepper, sprinkle with chopped fennel fronds, and serve, passing additional cheese.