Easy--but so tempting we only allow ourselves to have it about once a month, it IS rich!
But try not to worry about the fat content...recent nutritional research has calmed that bugaboo a LOT, realizing the good fats are GOOD for us. Your body--and your brain--appreciates good fats. Not margarine or poly-unsaturated over processed vegetable oils, of course, but butter, cream, olive oil and others, preferably organic, rock! Google "good fats" if you need convincing...
Posset is an ancient recipe, going back hundreds of years, in a variety of forms.
OUR favorite is scientific magic. Cream, sugar, and lemon juice, that's it. Give it a try!
2 C. heavy cream (we buy organic whipping cream, but if you have a source fresh from the farm, go for it!)
1/2 to 2/3 C. sugar (we get organic sugar, too...and yep, sugar's only an occasional treat, hence the attempt at self-control...)
5 T. lemon juice
Put cream and sugar in a deep, heavy saucepan and heat to boiling, but don't let it boil over! Keep stirring constantly. (If it appears to want to boil over, blow on the surface!) Simmer for 5 minutes.
Most recipes call for 2/3 C. sugar, but I used 1/3 C. this time and it was still perfect, just not quite as madly sweet.
Remove from heat, then stir in lemon juice. I usually use fresh-squeezed, but once when I discovered my lemon had gone bad I used a commercial lemon juice I picked up at Green Acres. Whole Foods, Trader Joe's, Thrive, Sprouts or similar probably has something comparable. It still worked, but the bottled stuff made for a stronger lemon flavor and a little more bite.
Allow to cool 15 minutes, then pour into 4 little ramekins or small glass bowls (or old fashioned coffee cups, or pretty tea cups) and then chill in the refrigerator for several hours...it will set up perfectly, the magic interaction of the boiled cream and lemon juice.
You can get fancy and add lemon or orange zest or other flavorings, or top with unsweetened whipped cream or fresh berries, but so far I haven't been tempted--it's wonderful just exactly as it is.