In a medium bowl, gently whisk together the boursin with the yolk. Then add the eggs, one by one. Then add the flour, the heavy cream, and the milk, little by little. Add salt and pepper, and set aside in the fridge.
Preheat the oven at 350°F.
Cut up the ham in small pieces. Run the frozen peas under cool water for a couple of minutes. Toss together with the ham.
Place the empty ramekins in a baking dish. Fill the baking dish with hot water so the water reaches about halfway up the ramekins.
Place the ham & peas at the bottom of the ramekins. Pour the boursin/milk mixture on top, and bake for about 25 minutes. (Note that cooking time varies greatly depending on thickness and height of the ramekins. A knife should come out clean and the top should be golden when done.)
We served them with a simple endive salad: wash and cut up the endives, discarding the tough foot of it. Add whatever fresh herbs you have on hand (parsley, dill, cilantro…) A walnut vinaigrette goes great with it: 1 part red wine vinegar, 2 1/2 parts olive, 1/2 part walnut oil, a dash of mustard, salt and pepper. Blue cheese crumbs or walnuts could also complement it nicely.