Pre-heat oven to 375°.
Divide pie crust into two portions. (This recipe makes two small galettes, and you'll prepare one at a time.)
On a sheet of parchment paper, roll half of the crust into a circle, about 7" in diameter.
Carefully slice the wheel of brie in half, horizontally. This will give you two circles of brie, half the thickness of the original wheel. Place one half of the brie rind-side-down in the center of one of the pie crust circles.
Arrange half of the sun-dried tomatoes over the brie. (If tomatoes are large, use kitchen shears to snip them into small pieces or strips.)
Sprinkle the brie and tomatoes with half of the rosemary, then drizzle with half of the olive oil.
Working your way around the circle, bring bare edges of pie crust up to overlap the edge of the brie. (If your crust is particularly delicate, using the parchment paper to help lift each section of pie crust can really help keep a the crust from breaking as you're doing this.)
Repeat with other half of pie crust, brie, and remaining ingredients, to make two galettes.
Using the parchment paper, slide each galette onto a rimmed baking sheet (or pizza stone), and brie is soft and bubbly and pie crust is golden brown - about 18-20 minutes.
Let cool slightly and serve.