1. Preheat oven to 365 degrees F. and grease a large baking sheet.
2. Form the sausage meat into sixteen patties.
3. Divide the feta among the patties and roll them up to form sixteen, 2 1/2-inch logs.
4. Heat the olive oil in a large nonstick skillet over medium heat.
5. Add the sausage pieces and fry until just cooked through and browned, about 6 minutes. Cool.
6. Lay one sheet phyllo on a board and brush with melted butter.
7. Lay another sheet on top and repeat with the remaining sheets, brushing with butter each time.
8. Sprinkle the phyllo sheets with the mint, some salt, and some pepper.
9. Cut the phyllo into sixteen 3-inch long, 1-inch wide rectangles.
10. Roll each phyllo rectangle around a piece of sausage.
11. Place sausage rolls, seam side down, on the baking sheet.
12. Repeat with the remaining sausage pieces.
13. Bake the rolls in the oven for 3 minutes.
14. Flip rolls over and continue baking until both sides are golden, about 3 minutes longer.