In a small bowl, mix together the olive oil, minced garlic, dried rosemary, dried thyme, smoked paprika, salt, and pepper to create a marinade.
Place the flank steak in a large zip-top bag or dish and pour half of the marinade over the steak. Seal the bag or cover the dish and let it marinate in the refrigerator for at least 30 minutes.
While the steak is marinating, place the halved baby potatoes on a large baking sheet. Drizzle with the remaining marinade and toss to coat evenly.
Roast the potatoes in the preheated oven for about 15 minutes.
After 15 minutes, remove the baking sheet from the oven and add the green beans and lemon slices around the potatoes.
Remove the steak from the marinade and place it on the baking sheet, directly on top of the vegetables.
Return the baking sheet to the oven and roast for an additional 15-20 minutes or until the steak reaches your desired level of doneness (135°F for medium-rare).
Once done, remove the baking sheet from the oven; allow the steak to rest for 5 minutes before slicing it thinly against the grain.
Serve the sliced steak alongside the roasted potatoes and green beans, garnished with fresh parsley.
Notes
Let the steak rest before slicing for better texture.