Preheat the oven to 375 degrees Fahrenheit. Cut the tomatoes in half lengthwise and place them on a baking sheet, inside facing up. Rub the exposed interior with the olive oil and sprinkle with the salt and pepper. Place the pan in the oven and roast until they have reduced by half in size and are a deep dark red (about 40 minutes to 1 hour, depending on the size of the romas). Remove and allow to cool for 20 minutes before placing the tomatoes in a food processor or blender and blending at a high speed until a smooth thick paste forms. Scoop it out into a bowl, cover, and keep refrigerated when not in use. Can be used as a dip, condiment, and as a substitute for tomato paste.