1 1/4 pounds sirloin (about one inch thick) or strip steak, trimmed of excess fat
1 bunch watercress, cleaned
1 crusty baguette
5 tablespoons extra virgin olive oil (EVOO), divided
2 tablespoons butter
Salt and freshly ground black pepper
1 cup flour
1 small onion, peeled
1 1/2 cups beef stock
1/3 cup sour cream
2 tablespoons freshly squeezed lemon juice, divided
2-3 tablespoons fresh chopped dill
2 teaspoons Dijon mustard
1 tablespoon white wine or cider vinegar (eyeball it)
2 rounded spoonfuls of dill pickle relish
3-4 radishes, sliced
1 head green leaf lettuce or other lettuce of choice, chopped
Pickled onions (optional)
Slice the steak into very thin slices no thicker than 1/4 inch. Chop watercress and reserve.
Cut baguette into four pieces and split – but do not separate them – so they open like a book. Place a large skillet over medium-high heat with two turns of the pan of EVOO and butter. Pat sliced meat dry and season with salt and pepper. Coat the pieces in flour, shake off any excess, then add to the hot pan. Grate the onion directly into the pan and cook 5-6 minutes, turning the meat occasionally.
Add stock to pan, bring up to a bubble and cook about a minute to thicken. Stir in sour cream, 1 tablespoon of lemon juice and dill. Season the sauce with pepper and remove from heat. While meat cooks, combine the mustard, remaining tablespoon of lemon juice, cider vinegar and remaining 3 tablespoons EVOO in a salad bowl with a fork or whisk. Stir in relish, add radishes, lettuce and pickled onions to the bowl and toss salad to combine. Season with salt and pepper to taste.
To serve, pile meat into the baguette pieces and top with watercress. Serve the salad alongside.