How to make it
For Salsa Macha: Toss the tomatoes with 1 tsp corn oil and roast in a 400°F oven until caramelized, about 40 minutes, and reserve. Toast the árbol chilies in a dry skillet over medium heat until fragrant, about 5 minutes, and reserve.
Add remaining corn oil to a skillet and cook over low heat for 2 minutes. Add garlic and simmer for 15 minutes. Remove from heat and add chipotles to soften in the oil-garlic mixture as it cools.
Crush peanuts in a food processor and transfer to a bowl. Add árbol chilies, tomatoes, and garlic chipotle mixture to the food processor and puree, slowly adding 1⁄2 cup water in a steady stream as the processor runs. Add olive oil using the same method. Add oregano and peanuts and pulse to a chunky texture.
Melt lard in a saucepan over medium heat. Add salsa and cook until it thickens, about 10 minutes. Add salt. Cool completely before serving.
For Camotes: Heat oven to 350°F. Toss the sweet potatoes, olive oil, and salt in a bowl to coat, then transfer to an oiled sheet pan. Roast in oven until a knife slides easily through, 30 to 40 minutes.
Remove sweet potatoes from oven, and when cool enough to handle, cut into 1⁄2-inch slices. Arrange the slices on a serving platter, drizzle with crema and salsa macha, and sprinkle with blue cheese. Serve warm.