Ingredients
⅓cupunsalted butter,cut into 5 pieces
3½cupsyellow onion,(2 medium), chopped
2tbspgarlic,(6 cloves), minced
⅓cupall-purpose flour
4cupslow-sodium chicken broth
28ozSan Marzano Tomatoes,(2 cans)
3sprigsbasil,plus more chopped for serving if desired
1parmesan rind,(4 inch)
2tspgranulated sugar,or to taste
salt and freshly ground black pepper
heavy cream,for serving, optional
Preparation
Melt butter in a large pot (6-quart) over medium-high heat. Add onion and saute for about 10 minutes until slightly browned and caramelized.
Reduce heat to medium, add garlic, and saute for 30 seconds. Add flour and cook, stirring constantly for 1 minute.
While whisking slowly pour in chicken broth. Cook and whisk for about 1 minute until the flour has blended in.
Add in tomatoes, basil, parmesan, and sugar, then season with salt and pepper to taste. Bring to a light simmer.
Reduce heat to low, cover, and let simmer, stirring occasionally (Scrape along the bottom of the pot when stirring). Cook for about 25 to 30 minutes until tomatoes start to break down.
Remove from heat. Remove basil sprigs and parmesan rind from soup then use an immersion blender to puree soup until smooth.
Serve warm topping servings with a swirl of cream, if desired, and chopped basil.
