1
Combine all marinade ingredients in a blender. Coat the chicken in the marinade and marinate overnight or for at least 4 hours.
2
Preheat the oven to 350°F.
3
Place the potatoes in a large saucepan and cover with cold water by two inches. Add a teaspoon of salt and bring to a simmer. Cook until fork-tender, then drain and let the potatoes dry for 10 minutes.
4
Combine the butter, cream, brown sugar and maple syrup in a small saucepan over medium heat. Whisk constantly and heat through, being careful not to let the bottom scorch.
5
Return the potatoes to the pot and mash with a potato masher. Fold in the cream mixture, along with the sour cream, pecans, vanilla and lemon juice. Season with salt and pepper.
6
Remove the chicken from the marinade, discard marinade and season chicken with salt and pepper. Roast on a baking sheet until cooked through, about 22-25 minutes.
7
For the chipotle sauce, melt the butter in a medium saucepan. Add the garlic and cook over low heat until softened, about 5 minutes. Add the flour, coriander, cumin and oregano and whisk to make a thick roux. Cook over medium heat until the flour turns light golden, stirring constantly, about 10 minutes.
8
Add the cream and bring to a boil. Reduce to as simmer and cook for 20 minutes. Fold in the chipotle purée and season with salt and pepper.
9
Toss the broccolini with the oil, garlic, salt and pepper on a baking sheet. Roast for 10-12 minutes, until crisp-tender.
10
To serve, divide the mashed sweet potatoes between plates. Top with chicken and broccolini and drizzle with sauce.