1 tablespoon grape seed oil or extra-virgin olive oil
1 teaspoon minced garlic
1 cup diced yellow onion
3/4 cup Massel vegetable or chicken-flavored broth
1/3 cup raw unsalted cashews, soaked and drained
1 1/2 teaspoons finely chopped fresh rosemary, plus more to taste
1 1/2 teaspoons Massel vegetable seasoning powder, plus more to taste
1/4 teaspoon freshly ground black pepper, plus more to taste
Place the chopped potatoes in a large saucepan, cover with water, and bring to a boil. Reduce the heat to medium-high, and simmer for 8 to 10 minutes until tender. Drain well.
In a skillet over medium heat, warm the grape seed oil, and sauté the garlic and onion for 5 to 10 minutes until soft and translucent and just starting to brown. Allow the mixture to cool for 5 minutes.
Pour the broth, cashews, rosemary, seasoning powder, and pepper into your blender, add the cooked onion and garlic mixture, and blast on high for 30 to 60 seconds, until smooth and creamy.
Transfer the drained potatoes into the bowl of your stand mixer, and begin whipping with the paddle attachment. Gradually pour in the blended mixture, and process for 10 to 20 seconds until the potatoes are light and fluffy. (You could also mash the potatoes by hand with a potato masher or ricer.)