Young Fontina, a superb melting cheese, adds lushness and a little tang to the strata. And remember to put whole nutmeg on your shopping list; a bit of the freshly grated spice amplifies the other flavors.
Prepare yourself for a few rousing verses of "For She's a Jolly Good Fellow," sung by the vegetarians in your group. Far from a limp and wilted also-ran or meatless mystery, this sandwich packs brightness (chickpeas gently mashed with lemon juice, lemon zest, and olive oil) as well as a mix of textures from the cheese, eggs, and fennel shavings.
Your local sandwich shop should consider itself warned: When you can make this reinterpretation of a classic Italian sub at home, you may not need to call in for one ever again. The arugula's kick blends with the heat of the soppressata. The fennel and fontina bring mellower flavors.