1 lg Flank steak, butterflied
1/4 c  Red wine vinegar
1 ts Garlic, finely chopped
1/2 ts Thyme, dried
1 bn Spinach
2    Carrots, peeled, cut in
-quarters lengthwise
2    Eggs, hard-cooked, cut in
-quarters lengthwise
1 md Onion, thin sliced and
-separated into rings
2 tb Parsley, finely chopped
1/2 ts Red pepper flakes
1 ts Sea salt
2 tb Vegetable oil
2 c  To 3 c beef broth

Place the meat in a glass dish. Mix together the vinegar, garlic and
thyme. Pour over the meat and let marinate for 1 or 2 hours at room
temperature.
Preheat the oven to 375 degrees F.
Wash the spinach under cold running water; drain and trim off the stems.
Spread the leaves evenly over the meat. Lay the carrots, in rows, across
the grain of the meat. Place the egg quarters between the rows of carrots.
Scatter the onion rings over the eggs and carrots, then sprinkle the
parsley, red pepper flakes and salt over all. Carefully roll up the meat
with the grain, jellyroll fashion. Secure with toothpicks and lace up with
string. Or tie with string at 1-inch intervals.
Heat the oil in a dutch oven. Add the meat and brown well on all sides.
Add the stock, cover tightly, and bake for 1 hour.
Remove the matambre from the pan to a board and let rest for 10 minutes.
Using a sharp knife, remove the strings and cut the roll into 1/4 inch
slices. Arrange on a heated platter and moisten with a little of the
cooking broth.
To serve cold: In Argentina, the matambre is poached, then removed from
the pot and pressed under weights until the juices drain off. It is
refrigerated until chilled, then served as a hors doeuvre, cut into thin
slices.