1. Fill a large pot fitted with a steamer basket with 2 inches of water. Place the cauliflower in the steaming basket. Bring the water to a simmer over high heat, then reduce the heat to low. Cover and steam the cauliflower until very tender and easily pierced with a fork, about 20 minutes. Drain.
2. Transfer the hot cauliflower to a clean kitchen towel and let cool for about 15 minutes, until cool enough to handle. Tightly gather the edges of the towel around the cauliflower and twist to form a bundle. Over the sink, wring out as much moisture as possible. 
3. Transfer the cauliflower to a food processor. Add the flour, and salt. Pulse until the mixture comes together and forms a slightly sticky dough, about 20 pulses. 
4. Turn the dough out onto a well-floured surface. With floured hands, gently form the dough into a ball and cut into 8 equal pieces. Working with one piece at a time, roll each portion into a ½-inch-thick log (the dough will be quite soft and loose). Cut each log into 1-inch pieces. If desired, gently roll each piece over the tines of a fork to create ridges.
5. Bring a large pot of salted water to a boil over high heat. Working in batches if necessary, add the gnocchi and return to a boil. Cook until the gnocchi float to the surface, about 3 minutes. Drain. 
6. Divide the gnocchi among 4 bowls and top with sauce. 

Notes