Centro's tomato basil soup doppelganger

If you've ever lived or worked in downtown Des Moines, you've likely had lunch at Centro, which hopefully included their tomato basil soup, which is delicious. I found this recipe on Breaking the Recipe Rut, made a few of my own changes - more basil, add tortellini, etc. It turned out so good - exactly like Centro's. 

Creamy Tomato Basil Soup
1/2 c butter
1 c flour
4 c chicken broth
3 1/2 c fat free half & half
1 1/2 c marinara sauce
1 can diced tomatoes, Italian style
1/4 c chopped fresh basil
1 package tortellini
Ground black pepper

Melt the butter in a large saucepan over medium heat. Whisk in flour and stir for 5 minutes to slightly brown the mixture. Whisk in the broth. Increase the heat and cook and stir until thickened. Decrease the heat to low, stir in the half and half and simmer for 20 minutes.

Meanwhile cook the tortellini according to package directions.

After the 20 minutes of simmering, stir in the marinara sauce, tomatoes, basil and tortillini and cook until heated through. Season to taste with salt and pepper.

A few notes: After you whisk the flour into the butter, it will look a little like sugar cookie dough. This was unexpected to me for some reason, but appears to be correct, so go with it. Also, I doubled the basil to 1/4 cup and thought it was perfect, but if you don't like basil as much as I do, go back to the 2 Tbsps recommended in the original recipe or 1/2 a teaspoon of dried basil. You can also switch to vegetable broth to make this vegetarian.