Wash potatoes and peel if desired (I like a more rustic mash, with peels on). Cut into quarters, and steam in a large stock pot with a metal steamer and plenty of water. Steam until potatoes are cooked through and tender when pierced with a fork, about 20-30 minutes. (You can also boil the potatoes if you don’t have a steamer.)

While the potatoes cook, melt butter in a large frying pan over medium flame. Add sliced garlic and rosemary leaves and swirl pan to begin to sauté. Watch over the next few minutes as the garlic begins to brown. When the edges are golden and starting to crisp, and it smells delicious, remove from heat.

When potatoes are cooked, remove from heat, drain water, and empty potatoes from steamer into drained stock pot. Mash with a potato masher until largely smooth, then add chèvre, sour cream, and sea salt.

Continue to mash until incorporated, then add almost all of the butter, garlic, and rosemary mixture, reserving a bit for garnish. Mix in thoroughly, and leave in covered pan until ready to serve. Serve garnished with reserved crispy rosemary, butter, and garlic pieces.