Pre-heat oven to 375F.

Cut tomatoes in half, and remove cores.

Place tomatoes in a baking dish (you may need to creatively arrange and/or use two dishes).

Season tomatoes with salt, pepper, garlic powder, and dried tarragon.

Drizzle a tablespoon or two of olive oil over the tomatoes.

Roast tomatoes for 45 minutes. No need to turn them.

Remove tomatoes from oven once they're cooked. I let them cool for a few minutes prior to blending, but if you decide not to, use caution. 

Add tomatoes and juice left over from roasting into blender (I do two batches), blend well.

Place a sieve over a pot and then pour blender mixture into the sieve. Using a spoon, strain the liquid through the sieve. Discard what's left in the sieve.

Add milk or half-and-half to the soup.

On medium-high heat, warm soup, stirring occasionally. Turn off heat just before soup reaches a boil.

Serve immediately, add additional salt & pepper to taste if needed.