Step 1 Using a mortar and pestle, or a coffee or spice grinder, coarsely grind together 1 teaspoon salt and the fennel seed. Cut the roast crosswise into slices that are one-fourth- to one-half-inch thick. Arrange on a plate and season with the salt and fennel seed mixture. Set aside at room temperature for at least 1 hour.
Step 2 Bring a large pot of water to boil. While waiting for the water to heat, strip the stems from the kale, and chop the leaves coarsely. Add the leaves to the boiling water and cook until they are tender, 5 to 7 minutes. Drain, squeeze dry and set aside.
Step 3When ready to cook, pour the oil into a large skillet and place over medium-high heat. Add the garlic cloves, and cook until they begin to brown. Remove with a slotted spoon and discard. Add the meat to the hot oil and brown on both sides, 2 to 3 minutes per side.
Step 4Remove the pork to a clean plate and put in a warm place. Reduce the heat to low, add the kale to the pan and cook, stirring to coat with the pan drippings, until the flavor mellows and combines, about 5 minutes. Season to taste with salt.
Step 5Arrange the pork on top of the kale, pouring any collected juices in the plate over the greens. Season with more salt if necessary, cover and cook over low heat until the pork is heated through, about 3 minutes. Serve immediately, spooning a mound of the greens onto the plate and placing the pork steak on top.