1/2 c. dairy sour cream
2 tbsp. sugar
1 tbsp. prepared horseradish
1/2 tsp. dry mustard
1/4 tsp. salt
3 tbsp. tarragon vinegar
7 c. torn fresh spinach
1 1/2 c. cream-style cottage cheese (12 oz.)
1/2 c. chopped walnuts

To prepare dressing, stir together sour cream, sugar, horseradish, mustard, and salt. Gradually blend in vinegar until well combined. Cover and chill.