For the gnocchi:
3/4 cup all-purpose flour, plus additional for dusting
1/4 cup (3 ounces) Wisconsin Parmesan cheese, freshly grated
Zest of 1 lemon, grated
1 cup (8 ounces) Wisconsin whole milk ricotta cheese, drained
For the sauce:
6 tablespoons unsalted butter
1/2 shallot, thinly sliced
12 sage leaves
1 garlic clove, thinly sliced
Juice of 1 lemon
2 tablespoons water
1/3 cup (about 2 1/2 ounces) Wisconsin Parmesan cheese, freshly grated
12 fresh parsley leaves
Make the gnocchi: Combine flour, Parmesan and lemon zest in bowl. Add Ricotta and egg. Mix well with wooden spoon or your fingers until dough just comes together. Do not overwork or dough can toughen.
Scrape dough onto a well-floured surface and form into a roll. Cut dough into fourths, using bench scraper or knife. Gently roll each piece into foot-long ropes, about an inch in diameter, flouring as needed to prevent dough from sticking to surface. Place dough ropes on lightly floured platter or sheet pan; refrigerate for 30 minutes or up to two hours, uncovered, to rest.
Place ropes on floured surface; cut into 1/2-inch pieces with scraper or knife.
Finish the dish: Heat butter over medium-high heat in sauté pan large enough to accommodate all gnocchi without crowding. When butter foams, add gnocchi—do not crowd—and cook, turning as necessary, until brown and crisped on all sides, 5-6 minutes. When gnocchi are almost cooked, lower heat to medium and add shallot and sage leaves. Cook briefly to release flavors; then add garlic, lemon juice and water. Cook briefly, allowing sauce to emulsify and thicken a bit. Add 1/3 cup Parmesan and parsley leaves. Toss to coat gnocchi. Spoon gnocchi and sauce into shallow bowls. Serve immediately.