Heat oil in a medium skillet over medium heat. Add sliced shallots and a pinch of kosher salt. Cook shallots until they begin to brown, turn heat to low, and cook until very soft about 15 minutes. Stir in another pinch of salt and fresh rosemary. Cook for another 2 minutes. Transfer to a bowl, cover, and refrigerate to cool.

Preheat oven to 375°F. In a large bowl, whisk together flour, baking powder, sugar, and salt. Use your hands to mix in cold grated butter until fully incorporated. Fold in cooked, chilled shallots.

In liquid measuring cup, whisk together non-dairy milk, coconut cream, and lemon juice. Drizzle over flour/butter mixture. Use wooden spoon/rubber spatula to combine until it starts to come together. Be careful not to overwork dough. The dough will be shaggy with some wet spots. Form dough into a loose ball and tightly wrap in plastic wrap. Refrigerate for at least 30 minutes.

Transfer chilled dough to lightly-floured surface. Using a floured rolling pin, flatten into ¾” thick rectangle. Add a couple slices of gruyere into the center of the rectangle. Fold one side into the center, then the other side. Turn dough horizontally, then flatten into a ¾” thick rectangle again. Add another layer of gruyere slices. Repeat this 2 more times. 

Cut dough into 3-inch circles with round biscuit cutter. Make sure not to twist the biscuit cutter when pressing down into the dough. Re-roll any scraps and cut more circles until all the dough is used up (it may be more than 8).

Arrange circles on parchment-lined baking sheet. Brush tops with non-dairy milk milk. Bake biscuits for 17 minutes until tops are light golden brown. While biscuits are still warm, brush over warm butter and sprinkle flaky sea salt.