1. In a large bowl, combine the steak cubes, minced garlic, olive oil, salt, and pepper. Toss until the steak is well coated. Cover and let it marinate in the refrigerator for at least 30 minutes, or up to 2 hours for more flavor.
2. While the steak is marinating, prepare your chimichurri sauce. In a medium bowl, mix together the parsley, cilantro, red wine vinegar, minced garlic, and red pepper flakes. Slowly whisk in the olive oil until well combined. Season with salt and pepper to taste. Set aside.
3. Preheat your grill to medium-high heat. If using wooden skewers, soak them in water for about 15 minutes to prevent burning.
4. Thread the marinated steak cubes, bell peppers, and onion chunks onto the skewers, alternating as you go.
5. Place the skewers on the preheated grill. Cook for about 8-10 minutes, turning occasionally, until the steak is cooked to your desired level of doneness and the vegetables are charred.
6. Remove from the grill and let rest for a few minutes. Serve hot with the chimichurri sauce drizzled on top or on the side for dipping.

The smell of the grilled garlic steak takes me back to those bustling apartment evenings, where the air was filled with laughter and the promise of good food.