Peel and dice the sweet potatoes into 2-inch pieces, steam them for about 20 minutes until fork-tender, and then let them cool.
Rice the potatoes or mash them well. Combine the potato, 3/4 cup flour, egg yolk, and salt with a fork and then your hands. Gently knead until the dough comes together. If it’s too sticky, add more flour (up to 1/4 cup).
Cover the dough and let it rest for 10-30 minutes.
Divide the dough into quarters and then each quarter in half. On a lightly floured surface, roll each piece into a log about 1/2” thick, then cut the gnocchi into 1/2” pieces. Optional: shape the gnocchi on a gnocchi board or using a fork.
Bring salted water to a simmer/light boil and cook the gnocchi until they begin to float, about 2 minutes. Strain 30 seconds after they float.
Sauce them up with your favorite pasta sauce right away, or if you like them crispy, sear the gnocchi before serving. We added butter to a pan with rosemary and fresh sage, let it crisp for a minute, then added in half of the gnocchi and let it crisp up for a few minutes.
We also added a splash of white wine, fresh minced garlic, salt, pepper, parmesan, and a bit of lemon zest. Feel free to play around with the ingredients to suit your taste!