1poundbeef sirloin tip steak,cut into 1-inch cubes
1mediumsweet onion,cut into ¾-inch wedges
1smallyellow squash,cut lengthwise in half, then crosswise into 1-inch slices
1smallzucchini squash,cut lengthwise in half, then crosswise into 1-inch slices
3smallbell peppers, any color,cut into 1-inch pieces
1poundmedium red skin potatoes,cut into 1-inch pieces
12mediummushrooms,cleaned and stems removed
Marinade
2tablespoonswater
2 tablespoonsred wine vinegar
1tablespoonDijon mustard,optional
1tablespoonbrown sugar
2clovesgarlic,minced or ½ teaspoon garlic powder
1teaspoonItalian seasoning
2teaspoonsvegetable oil
½teaspoonscoarse ground black pepper
Instructions
If using wood skewers, soak in water for at least 10 minutes. Flip after 5 minutes if not fully submerged.
Combine marinade ingredients in small bowl. Place beef and marinade in food-safe plastic bag. Close bag securely and marinate in refrigerator 4 hours or overnight, turning occasionally.
Place potatoes in microwave-safe dish and cover with vented plastic wrap. Microwave on high for 5 minutes or until just tender, stirring once. Cool slightly.
Fire up the grill while potatoes are cooking.
If using wood skewers, remove skewers from water.
Remove beef from marinade and place in bowl. Discard marinade.
Alternately thread beef, onion, pepper, squash, beef, mushroom, potato, onion, etc., onto skewers, or invite everyone to build their own kabobs by mixing and matching their favorite vegetables with the sirloin tip steak.
Place kabobs on grill over medium, ash-covered coals. Grill covered, turning every 3-4 minutes on each side or until desired doneness is reached (see recipe notes for how to measure doneness).
Let beef rest for a few minutes before serving. For extra tender kabobs, rest for 3-5 minutes wrapped in foil before serving.
Notes
How to check steak for doneness using an instant-read thermometer
For steaks ½ inch or thicker, insert thermometer horizontally from the side, so that it penetrates the thickest part or the center of the sirloin.
For medium rare, cook until the temperature is 145 F.
For medium, cook until the temperature reads 160 F.
For well done, cook until the temperature reads 170 F.