Preheat the oven to 220C, fan-forced. Line a large oven tray with baking paper. Cut the unpeeled potatoes into 1.5cm-thick fries. Put on the lined tray, drizzle with 2 tsp olive oil, season with salt and pepper and toss to coat. Bake for 25 mins or until golden and tender.
Step 2 — Prep vegetables
While the potato frites are baking, trim the beans. Discard the tough stems from the kale and coarsely tear the leaves. Very finely chop the onion.
Step 3 — Season steaks
Combine 1½ tsp pepper and garlic seasoning (reduce the seasoning for a milder pepper kick) and 2 tsp olive oil in a large bowl and season with salt. Add the steaks and turn to coat.
Step 4 — Cook greens
Melt 15g butter in a medium frypan over medium-high heat. Add the beans and kale and cook, stirring regularly, for 4-5 mins until tender and slightly charred. Remove from the pan, season with salt and pepper and keep warm.
Step 5 — Make sauce
Heat 2 tsp olive oil in the same pan over medium heat. Cook the onion, stirring, for 3-4 mins until softened. Increase the heat to medium-high, add the cream, 1½ tsp pepper and garlic seasoning, 1 tbs water and 1 tsp dijon mustard and cook, stirring occasionally, for 2-4 mins until slightly reduced. Taste, then season with salt and pepper.
Step 6 — Cook steaks and serve
Meanwhile, heat a medium frypan over high heat until hot (see cooking tip). Reduce the heat to medium-high and cook the steaks for 2-3 mins each side for medium-rare, or until cooked to your liking. Remove from the pan and rest for 3 mins. Divide the steaks, frites and buttered greens among plates. Drizzle the sauce over the steaks to serve.