Sauté onions in warm oil. Add the peas and steam.
Add long-grain rice and soup, simmer gently with lid on for about 10 minutes. Add spinach, mash, cool. Stir in buttermilk. Cover and let cool for about 2 hours. Fold in cream, season, garnish.
Tip: Did you know that one bowl of spinach already covers the entire daily requirement of vitamin K and beta-carotene?