Trim zucchini ends and slice on an angle into 1/4" rounds. Peel and cut sweet potato into 1" dice. Trim and thinly slice green onions on an angle, keeping white and green portions separate. Keep grains of paradise in their shipping bag and, using a small pan, crack into a coarse powder. A meat mallet, spice grinder, or mortar and pestle are also great tools for this. Don't worry if some larger chunks remain. Rinse steaks, pat dry, and season with a pinch of salt and grains of paradise. Lightly press grains into steak.

Bring a small pot with potatoes and enough lightly salted water to cover to a boil. Reduce to a simmer and cook 12-15 minutes, or until tender. Arrange zucchini slices on prepared baking sheet, drizzle with 1 tsp. olive oil, and season with a pinch of salt and pepper. Roast 8-10 minutes, or until tender and slightly caramelized.

When potatoes are tender, drain in colander and return to pot. Add 2 Tbsp. evaporated milk and 1/3 the butter. Mash with a potato masher or fork until smooth. Season to taste with 1/2 tsp. of salt and a pinch of pepper. Set aside and keep warm.

Heat a medium pan over medium heat. Add 1/2 the remaining butter and 1 tsp. olive oil to pan and melt. Add steaks to hot pan and cook 4-5 minutes per side, or until well-browned and steaks reach a minimum internal temperature of 145 degrees. Remove steaks to a plate and return pan to medium-high heat (no need to wipe clean).

Add 1 tsp. olive oil to pan and white portions of green onion. Cook 1 minute, stirring constantly. Add sherry and cook 2 minutes, or until mostly evaporated. Add remaining evaporated milk and bring to a simmer. Cook 5 minutes, or until sauce is thickened. Remove from heat and swirl in demi-glace and remaining butter. Season to taste with a pinch of salt and pepper.

Place a serving of zucchini and sweet potatoes on a plate. Serve steak against vegetables and ladle sauce in front. Garnish potatoes with remaining green onions.