For the rissole cakes, boil the squash cubes for the rissole cakes until just tender, and drain well. Set aside until needed. At the same time, boil the potatoes until soft and drain well.
Begin the sauce while the squash and potatoes for the rissole are boiling. Melt 2 tablespoons of the butter over medium heat in a saucepot (reserving the other 2 tablespoons) and cook the onion until translucent. Add the chicken stock, vinegar, soy sauce, and potato chunks and let the potato chunks cook while the liquid reduces and thickens.
For the chicken, preheat oven to 375 degrees F. While the chicken stock mixture is cooking for the sauce, season chicken breasts with salt, pepper and lime powder. Heat the grapeseed oil over medium high heat in a separate large skillet and sear the chicken leaving undisturbed for the first 3 minutes or so on each side to let the seasonings integrate into the surface of the chicken and allow the caramelization process to begin to prevent tearing of the chicken or "crusting off" of the seasonings. After the chicken is seared on both sides, transfer to a baking sheet and finish chicken in the oven.
For the garnish, boil asparagus spears until just tender in salt water and set aside.
In the same pan you used to sear the chicken, heat additional grapeseed oil (if needed) and saute the white onion until tender. Transfer the onion to the potatoes which have been boiled for the rissole cakes, reserving the saute pan. Season, to taste, with salt and pepper, and mash together. Fold in the white chocolate chips, scallions, cranberries, and cubes of squash, trying not to break up the squash. Allow to sit until cool enough to handle, then use a 3-inch circle cutter to form rissole cakes. In the same pan, heat additional grapeseed oil (if needed) over medium-high heat and sear the rissole cakes. Leave undisturbed for the first 2 to 3 minutes on each side to let the caramelization process begin and to prevent the cake from breaking apart. When you see the edges of the cake beginning to turn golden brown, flip and sear the other side. Then cook further until the cake is firm. Remove from heat and keep warm.
In the same pan, sear the asparagus spears for a few minutes to add a little color and a nutty flavor.
Return to the pot of the chicken stock mixture which has been cooking for the sauce. Fold the white chocolate chips into the sauce, and transfer the sauce to a blender and puree until smooth. Whisk in the reserved 2 tablespoons butter to finish the sauce, and season to taste with salt and pepper.
Place a rissole cake on serving plate, top with a chicken breast, spoon sauce over and garnish with asparagus spears.