Preheat oven to 450. Toast fennel seeds in skillet over medium heat. Let cool, grind. Stir in pepper, coriander and salt.
Season chicken with mixture. Place chicken in ovenproof skillet, and roast until cooked through, about 10 min. per side.
Heat olive oil in saucepan over medium-high heat. Add garlic, and cook until lightly browned. Add potatoes, thyme and wine; lower heat to medium, cook, stirring constantly, until wine is absorbedab out 7 minutes.
Add squash and 3/4 cup of broth and cook, stirring, until broth is absorbed, adding up to 3/4 cup more as needed until vegetables are tender. Stir in spinach leaves and parmesan, remove from heat.
Remove chicken from pan and pour off excess butter. Add 1/2 cup broth and place over medium heat. Cook until reduced to 2 Tb, about 4 minutes. Stir into risotto.