This is one of our favourite
frittatas . Put oil and butter in a
large (12 inches -30 cm) non - stick skillet , add onions ,salt
lightly , cover and let sauté
over moderate heat , stirring frequently , until
light golden brown (it takes about
15 minutes) .
Beat well eggs with
a pinch of salt and pepper , milk
and Parmigiano . Pour the mixture in
the skillet over brown onions . Let sauté
just for a few seconds over
moderate heat moving gently the mixture
with the apposite tool (to not
scratch the skillet).
Reduce heat to the
minimum (using a heat spreader )and let cook covered for
about 15 minutes .
The most famous tuscan
chef , Pellegrino Artusi who lived
in late 1800 , says "don't absolutely
turn the frittata" . This is a very
good hint that simplifies the cooking
of any sort of frittata .
So , after cooking , you can
put a large dish over the skillet
and turn upside down your frittata .
Serve at room temperature with a
fresh lettuce or tomato salad . You
can dice this frittata and serve
at a cocktail party