Bring a large pot of water to a roaring boil and cook the pasta as instructed on the box. Drain and toss with olive oil until ready to use. If using fresh homemade spaghetti, cook for 4 minutes. Brush off any dirt from the shiitakes and cut off the last part of the stem, if needed. Heat 2 tbsp of olive oil in a large saucepan, and toss in the shiitakes. Cook over medium/medium-high heat until begining to brown, about 5 minutes, stirring occasionally.
Turn the heat to medium-low and toss in the minced shallots and garlic. Sauté for about 60 seconds, stirring frequently to prevent burning. At 60 seconds, add the brandy, cognac or white wine, and allow it to burn off for 30 seconds before pouring in the chicken stock. Simmer until it is reduced by 1/2 and is slightly syrupy, about 12 minutes. Once reduced, pour in the 4 tbsp of fresh squeezed lemon juice and add the butter to the pan.
While the sauce is simmering, in a seperate small pan, heat canola oil over medium-high heat. Once hot (it should sizzle if a drop of water touches the oil), carefully add the drained, patted dry capers to the oil. Fry the capers, stirring frequently, until crispy and begining to brown, about 3 minutes depending on the heat of the oil. Drain the capers.
Now, spoon about 4 tbsp of liquid from the pan sauce into a small bowl. Mix in 1 tsp of corn startch to the bowl until there are no clumps, and pour this mixture back into the sauce. Stir to combine, and increase the heat to medium for 3 more minutes, stirring occasionally.
While the sauce is cooking, make the yogurt sauce. In a bowl, combine the yogurt, honey and 1 tbsp of lemon juice together, stirring well. Adjust lemon and honey according to taste.
Plate the pasta, then pour the shiitake lemon butter sauce over the pasta. Spoon a dollop of lemon honey yogurt sauce on the pasta, and sprinkle with fried capers and optional parsley/parmesan. Enjoy!