1-First Step: Prepare the meat and vegetables Start by cutting 1.5 pounds of sirloin steaks into 1-inch cubes if they are not already prepped. Try to keep the pieces close in size so they cook at the same rate. Wash the peppers, trim the mushrooms, and slice the red onion. If you are using wooden skewers, soak them in water for at least 30 minutes so they do not burn on the grill.

2-Second Step: Mix the marinade In a medium bowl, whisk together the 3 tablespoons red wine vinegar, 2 tablespoons olive oil, 1 tablespoon unspecified ingredient, 1 teaspoon unspecified ingredient, 1 teaspoon unspecified ingredient, 1 teaspoon unspecified ingredient, 1 teaspoon unspecified ingredient, and 1/2 teaspoon salt. Since the prompt includes some unnamed items, keep the marinade list exactly as provided. Pour the marinade over the steak cubes in a bowl or zip-top bag and toss until all pieces are coated. Let the beef marinate in the refrigerator for 30 minutes to 2 hours. This gives the meat time to absorb flavor without turning mushy. If you are in a hurry, even 20 minutes helps.

3-Third Step: Prep the skewers Thread the beef onto skewers, alternating with the red bell pepper, yellow bell pepper, green bell pepper, mushrooms, and red onion slices. Keep enough space between pieces so the heat can move around the kabobs. Do not pack everything too tightly, or the vegetables may steam instead of getting a nice grill mark.

4-Fourth Step: Preheat and oil the grill Heat your grill to medium-high, about 400 to 450 degrees Fahrenheit. Lightly oil the grates with a folded paper towel dipped in oil or use a grill brush. This helps keep the low carb kabobs from sticking and makes flipping much easier. If you are cooking indoors on a grill pan, let it get fully hot before adding the skewers.

5-Fifth Step: Grill the kabobs Place the kabobs on the hot grill and cook for about 4 to 5 minutes per side for medium-rare beef. Turn them only once if you can, so you get better grill marks. The total cook time is usually 8 to 10 minutes, depending on the size of the cubes and the heat of the grill. Use a meat thermometer if you want exact doneness. Aim for 135 degrees Fahrenheit for rare or 145 degrees Fahrenheit for medium. If you like your steak more done, leave it on a little longer, but watch closely so it does not dry out.

6-Final Step: Rest and serve Move the kabobs to a plate and let them rest for 3 to 5 minutes before serving. This helps the juices stay in the beef instead of running out when you bite in. Serve them hot with a simple side salad, cauliflower rice, or roasted low carb vegetables.