Gently drizzle and toss the sliced tomatoes in the olive oil to coat slices. STEP 2 Place slices without overlapping onto dehydrator shelves or a baking pan. STEP 3 If you are baking preheat oven to 200 degrees F. STEP 4 In a small bowl whisk together the remaining ingredients. STEP 5 Sprinkle mixture over each slice. STEP 6 Depending on how thick the slices of tomato are, dehydrating could take anywhere from 12-24 hours. STEP 7 If baking check every 30 minutes until edges show some charring, could take 4-5 hours.