To prepare sauce, combine first 6 ingredients in a bowl, stirring well. Cover and chill.
To prepare cakes, heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add leek to pan; sauté 3 minutes or until tender. Place leek in a large bowl. Wipe pan with paper towels.
Place potato in a sieve; gently squeeze potato to remove excess moisture. Add potato, flour, 1/2 teaspoon salt, 1/2 teaspoon pepper, and eggs to leek in bowl; stir well. Return pan to medium-high heat. Recoat pan with cooking spray. Divide potato mixture into 16 equal portions, shaping each into a 1/4-inch-thick patty. Add 8 patties to pan; cook 5 minutes on each side or until golden. Repeat procedure with remaining 8 patties. Serve with sauce.
We loved these as a side dish with a chicken sausage and some beet greens. I cut the recipe by 25% for me and spouse, and it was just right. I used nonfat plain yogurt in place of sour cream, yellow onion in place of leeks, dried chives instead of fresh, and subbed 2 TB liquid egg whites for the 1/4 egg that would have been needed.I also used a reduced fat blue cheese. And I added ground red pepper to the sauce. These were small changes that probably didn't affect the flavor much. Okay, and the biggest change was that I used the one teaspoon of bacon fat left over from morning bacon as shortening in the iron skillet. The whole thing was delicious!
I didn't really taste the leeks but was pleased at how easily these cakes went together. We served them along side the Ginger-Thyme Brined Pork Roast as pictured in the magazine. The sauce was interesting - next time I'd make it ahead of time as the sauce was more flavorful the next day. These cakes would make a great accompaniment to grilled steaks.