Kale and Potato Spanish Tortilla

A Spanish tortilla is essentially a frittata, hearty and protein-packed.
Serves 6
1 pound fingerling potatoes
1 cup olive oil
2 shallots, chopped
1.5 tsp salt
1 bunch kale, center ribs discarded
7 large eggs
Scrub the potatoes and dice them into 1/2 inch cubes to measure 2.25 cups. Heat oil in a non-stick skillet over moderate heat until hot but not smoking. Reduce heat to moderately low, add potatoes, shallots and 1 tsp salt. Cook, stirring occasionally, until potatoes are tender - about 20 minutes.
Meanwhile, cook the kale in a 4-6 quart pot of boiling salted water (1 Tbs. salt per every 4 qts. water), uncovered, until wilted, 2-3 minutes. Drain, then immediately transfer to a bowl of cold water to stop the cooking. Drain again and squeeze out the water from handfuls of kale. Chop coarsely.
When potatoes are tender, add kale and cook, stiring occasionally, until tender, about 5 minutes. Drain veggies in colander set over a bowl, reserving the oil, and let cool for 10 minutes.
Lightly beat the eggs in a large bowl. Stir in the veggies, 1 Tbs. reserved oil, and remaining 1/2 tsp. salt.
Add 1 Tbs. reserved oil (save the rest for use another time) to same skillet, then add egg mixture, cover and cook over low heat until edges are set but center is still soft, about 12 minutes. Remove from heat and let stand, covered, for 15 minutes; eggs will continue to cook slightly.
Shake skillet gently to make sure tortilla is not sticking to it (if it is, loosen it with a heat proof plastic spatula) and slide tortilla onto a large flat plate. Invert skillet over tortilla and, using pot holders to hold plate and skillet together tightly, flip it back into skillet. Round of edges of tortilla with plastic spatula and cook over low heat, covered, for 10 minutes more, or until cooked through. Slide tortilla onto a plate and serve warm, cut into wedges.