Originally from the Silver Spoon Cookbook- Kosher cooking for the discerning palate. This sauce goes well over recipe #645 - Gourmet Napoleons.
2 medium onion, diced
4 Tbsp oil
1 stalk of celery, thinly sliced
1 red pepper, diced
1 (8 oz) can mushrooms- drained - reserve liquid
3 tsp cornstarch (diluted in ¼ cup water)
1 tsp flat salt
½ tsp garlic powder
⅛ tsp white pepper
1½ tsp paprika
Saute the onion in the oil until translucent. Add the celery and pepper. Saute for an additional 10-15 minutes.
Add the mushrooms. Let cook 5-7 minutes. Pour in the dissolved cornstarch and stir vigorously. Add the spices while stirring.
Add spices. Pour in reserved liquid. Keep on mixing until liquids and vegetables are well combined.
Bring to a boil. Allow to cook 10-15 minutes, or until sauce has reached desired consistency.