Preheat oven to 400°. Lightly butter an 8-inch square baking dish.
Trim fennel bulbs; halve, and core.
Slice bulbs and potatoes very thin (1/8 inch thick).
Add potatoes to prepared dish in three layers, alternating two layers fennel. Season each layer with coarse salt and ground pepper, 2 tablespoons grated Asiago cheese, and dot with ½ tablespoon butter. (Omit cheese from final layer).
Over top of final layer of potatoes, pour heavy cream. Bake until potatoes are tender when pierced, about 45 minutes.
Sprinkle with ½ cup grated Asiago cheese; bake additional 15 to 20 minutes, until golden brown.
Recipe by Kuhn Orchards at https://kuhnorchards.com/fennel-and-potato-bake/