Remove leaves from cauliflower head, core, and cut into large florets. Add cauliflower florets to boiling water and cook until tender, 6-8 minutes. While cauliflower boils, mince chives. Peel and halve shallot. Slice halves into thin strips. Trim ends off green beans. Pat steaks dry, and season both sides with a pinch of salt and pepper.

Drain cauliflower in a colander and return to pot. Add blue cheese, half the milk, half the butter (reserve remaining for sauce), and chives (reserving a pinch for garnish). Mash, adding remaining milk 1 Tbsp. at a time, until desired consistency is reached. Set aside.

Heat 1 tsp. olive oil in a medium non-stick pan over medium-high heat. Add steaks to hot pan and cook until steaks reach a minimum internal temperature of 145 degrees, 3-4 minutes per side. Remove steaks to a plate and cover with foil. Reserve pan; no need to wipe clean.

Return pan used to sear steaks to medium heat. Add remaining butter and melt. Once melted, add shallots and stir occasionally, 1-2 minutes. Add white wine and cook until mostly evaporated, 30-60 seconds. Add demi-glace and Dijon and stir until thick enough to coat the back of a spoon, 1-2 minute. Remove from burner and set aside.

Heat 1 tsp. olive oil and 2 Tbsp. water in another medium non-stick pan over medium heat. Add green beans to hot pan. Once beans start sizzling, cover and cook until tender, 5-7 minutes. Season with a pinch of salt and pepper.

Add mashed cauliflower and green beans to a plate. Nestle steak onto mashed cauliflower and drizzle with sauce Robert. Garnish cauliflower with remaining chives.