HIT THE HEAT
In a large skillet fitted with a lid, melt the butter over medium-high heat. Add the sliced fennel and 1/4 tsp salt and cook, stirring occasionally, until the fennel begins to brown, about 5 minutes.
Lower the heat to low and pour in the cream. Stir to scrape up any browned bits from the bottom of the pan.
COVER AND SIMMER
Cover the pot and simmer, stirring occasionally, until the fennel is tender when pierced with a fork, about 10 minutes.
FINISH THE DISH
Stir in the cheese and half of the reserved fronds; season with salt and pepper. To serve, garnish with the remaining reserved fronds and a sprinkling of cheese.