Heat a large skillet over medium-high heat and melt 2 tablespoons of butter and 1 tablespoon of olive oil together. Add the diced baby potatoes, seasoning them generously with salt, pepper, dried rosemary, and thyme. Sauté for about 10-12 minutes until they are golden brown and fork-tender.

Once the potatoes are done, create space in the skillet and add another tablespoon of butter. Sear the seasoned sirloin steak bites in the same skillet for 2-3 minutes per side, ensuring they are juicy and flavorful.

Lower the heat to medium and add the remaining 2 tablespoons of butter to the skillet along with the minced garlic. Sauté the garlic for about 1 minute, or until fragrant but not browned.

Return the cooked steak bites and crispy potatoes to the skillet, tossing everything together to coat in the garlic butter.

Remove from heat, transfer to a serving platter, garnish with parsley, and serve immediately.