Ingredients
3/4 cup extra virgin olive oil
2 pounds beef top sirloin, cut into 1-inch cubes
Salt and pepper to taste
16 small red potatoes
12 sweet onions
16 mushrooms, stemmed
4 tomatoes, coarsely chopped
2 cucumbers, sliced
4 scallions, chopped
Juice of 1 lemon
1/2 cup steak sauce (optional)
1/4 cup spicy mustard

Preparation
-Pre-heat a grill to medium-high or the broiler to high. Pour 1/2 cup Olive Oil into a bowl. Thread the beef cubes onto 4 skewers and brush with the Oil in the bowl; season with salt and pepper.

-In a medium pot, cover the potatoes with water and bring to a boil. Cook until just tender, 11-12 minutes; drain and let cool. Thread onto 2 skewers, brush with Olive oil and season with salt and pepper.

-While the potatoes are cooking, bring a large saucepan of water to a boil. Add the onions and cook for 5 minutes, then rub off the skins with a towel. Thread the onions onto 2 skewers, brush with Olive Oil and season with salt and pepper. Thread the mushrooms onto 2 skewers and brush with oil; season with salt and pepper.

-Grill or broil the mushrooms until tender, 12-15 minutes. Grill or broil the beef, potatoes and onions, turning every couple of minutes.

-In a bowl, combine the tomatoes, cucumbers and scallions. Toss with the lemon juice and remaining 1/4 cup olive oil; season with salt and pepper. In a small bowl, mix the steak sauce and mustard.