In a large saucepan, add onion, peas, spinach (no need to drain liquid), and tarragon. Cover with water or broth; start with 4 cups and add the remainder if needed during blending. Bring to a simmer and simmer for about 20 minutes until vegetables are tender.
Blend well until smooth. Wipe pan clean and return mixture to pan. Heat through, add Sherry, cream (or half and half), and curry powder. Warm and remove from heat before the mixture comes to a boil. Taste and add salt if desired.
Serve with garnish of your choice; the soup may be served warm or cold.
Nutrition:
Made with half & half: Calories 217; Total Fat 8 g 12 %; Saturated Fat 5 g 23 %; Monounsaturated Fat 2 g; Polyunsaturated Fat 1 g; Trans Fat 0 g; Cholesterol 22 mg 7 %; Sodium 87 mg 4 %; Potassium 672 mg 19 %; Total Carbohydrate 25 g 8 %; Dietary Fiber 8 g 33 %; Sugars 8 g; Protein 10 g 21 %; Vitamin A 187 %; Vitamin C 57 %; Calcium 22 %; Iron 18 %