Preheat heat oven to 400F. Cook olive oil and butter in a skillet over medium heat, stirring constantly, 3 to 4 minutes or until butter begins to turn golden brown. Remove butter mixture from heat, and add peeled potatoes, tossing gently to coat.
Spread potatoes in a single layer in a 15 x 10 inch jelly roll pan.
Bake at 400F for 40 to 45 minutes until potatoes are golden brown and tender, stirring twice. Transfer potatoes to a large serve serving bowl, and toss with lemon juice, chopped fresh thyme, salt and pepper until well coated. Serve potatoes immediately