I made this up, and I'm hoping my memory is serving me well here. Came out absolutely delicious:
2 T olive oil
2 T butter
1 large red onion or 2 small red onions, chopped
5 cloves garlic, chopped
Kosher salt and freshly ground pepper
2 1/2 T flour
1 small can tomato paste
1 box (2 1/2 Cups, I think) vegetable broth, warm
2 Roma tomatoes, seeded and chopped
1 large can (20 oz) diced tomatoes
One handful fresh basil, washed well
1/2 C heavy cream or half and half
In a large, heavy bottomed pot, melt butter and oil together over medium heat. Add onions and garlic and salt and pepper well. Cook gently until onions soften, careful not to burn garlic.
Sprinkle in flour and stir well for 3 minutes. Add tomato paste and stir well. Slowly add in warm vegetable broth and stir with a whisk as the combination thickens. Add chopped tomatoes and can of diced tomatoes and stir well. Don't let the mixture come to a boil. Simmer for about 15 minutes.
Throw in basil for last 3 minutes. Remove from heat and stir in cream.
Ladle into a blender, working in batches. YOU MUST REMOVE THE LITTLE CAPPY THING ON THE BLENDER COVER AND HOLD TOP DOWN WITH A TOWEL. I learned this the hard way - when you blitz hot things in a blender it makes the top blow off. My old condo's kitchen looked like a Tarantino film the first time I made this.
Anyway, blend in batches and blend really well until it's nice and smooth. Taste and adjust seasonings (sometimes I make this when I'm sick and I'll add a clove of raw garlic to help me heal).
