Paprika sauce

This recipe is a variation of the late Jeff Smith's from his cookbook The Frugal Gourmet on our Immigrant Ancestors. I wouldn't call it authentic Hungarian, but it is delicious on stuffed peppers, meat, sauerkraut, maybe even an old shoe.

Ingredients
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2 TB freshly rendered lard (or substitute vegetable oil)
1 large yellow onion, minced
2 cloves garlic, peeled and minced
2 TB Hungarian paprika (or more to taste)
2 c. mild green chiles, seeded and minced (anaheim, cubanelle, or poblano)
8 oz tomato, chopped (or substitute tomato sauce or puree)
1 tsp chicken base, low salt
4 c. beef stock
1/4 c. flour
1 c. sour cream

Preparation
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In a small bowl mix 1 cup of the beef stock and half of the flour into a lump free slurry, then set aside.
In a 3 qt sauce pan heat the lard and sweat the onion on low heat until soft.
Add the garlic and paprika and cook for a few more minutes.
Add the beef stock/flour mixture to the pan, increase the heat to medium and simmer for about ten minutes.
In a small bowl mix the sour cream and remaining flour thoroughly, then set aside.*
Add the chiles, tomato, chicken base and remaining beef stock and simmer for 30 minutes or until reduced by half.
Reduce the heat to low, add the sour cream mixture, bring to a simmer and cook for 5 minutes.
Remove from the heat, let sauce cool, pour into a blending container and blend until smooth.

*If you intend to freeze the sauce, leave out the sour cream / flour mixture and add it later.