Put the cutlets one at a time between two pieces of plastic wrap or parchment paper and gently pound on the cutlet using a meat mallet or the back of a heavy object.
Sprinkle both sides of the beef cutlets with salt and pepper.
Prepare 3 bowls; in the first one, put the eggs; in the second one, the flour; and in the third one, the breadcrumbs. Chop the rosemary and mix it with the bread crumbs (in the third bowl).
Now, dredge each cutlet in flour first (shake off any excess flour). Then, dip into the beaten eggs (drip off any excess). Finally, dredge in the breadcrumb mixture (make sure both sides are completely covered).
Heat the oil in a large frying pan over medium-high heat. Add the breaded cutlets to the hot oil and fry for 2-3 minutes per side until golden brown.
Garnish with fresh thyme and serve warm.
Notes
Don't overcrowd the pan; cook the cutlets in batches in single layers.