Pre-heat oven to 400F degrees. Add the tomatoes to a small baking dish. Season with oil, rosemary, salt and pepper and roast for about 20 minutes.
Yucca
Remove the thick skin from the yucca root and cut into slices, than cut each slice into quarters. Bring to a boil with a pinch of salt. The water level does not need to cover the yucca completely. Boil for 15-20 minutes or until fork tender. Remove the soft yucca from the stove and drain the remaining liquid. Place the yucca chunks in a small bowl and mash. I used a table folk to mesh the yucca. Add the butter and coconut milk and continue to mash until you reach a smooth consistency.
Pistachio Paste
Add the pistachios to a food processor and blend until it reaches a grainy consistency. Add the garlic, oil, salt and pepper and process for another minute until a paste like mixture.
Crostini
Thinly slice the baguette. Add a layer of yucca, a layer of pistachio paste an top with1-2 roasted tomatoes. Serve cold.
Refrigerate remaining ingredients to be re-used within 4-5 days.