I baked these in a muffin tin with no harm done – though the wise would take note and very, very genorously grease the pan as I had quite a ridiculous amount of sticking going on despite my spritz of non-stick spray.
Whisk together 3/4 c whole milk, 1/4 c water, 2 large eggs, and zest from a lemon (2 t?) in a bowl. I love the lemon flavor so next time I might consider adding lemon juice in lieu of water – can someone (Jen?) tell me how adding that acid might affect the chemistry? Whisk in 1 T melted butter. Add 3/4 c plus 2 T flour and 1/2 t each salt and pepper and whisk until mixed, but batter will still be lumpy.
Divide batter in pan, if using muffin tin, about 1/2 c batter per muffin will do. Sprinkle with additional freshly cracked pepper. Bake at 375 for 30 minutes (for muffin tin) or 40 minutes (for traditional popover tin). Slit each popover with a knife and bake an additional 5 minutes. Remove, devour.