Preheat oven to 400 degrees.
Slice and core tomatoes. May mix different varieties and sizes. Drizzle with olive oil, sprinkle with kosher salt, pepper, and sliced garlic.
Bake 30 to 60 minutes, until juices have evaporated. Store in a plastic qip-top bag in refrigerator or freezer. You can also slow roast tomatoes in a 250 degree oven for 3 to 4 hours.