For the spinach, heat a medium-size skillet over medium heat with the oil, 2 turns of the pan. Add onions or shallots and garlic, and soften 5-7 minutes. Melt in cream cheese, , add cream or half-and-half to thin a bit, and season with nutmeg, salt and pepper. Add spinach and heat through; add grated cheese.
For the burgers, combine sirloin with Kosher salt, Worcestershire and pepper, and form 4 large patties that are thinner at center and thicker at edges for even cooking. Heat a skillet over medium-high and cook burgers 3-5 minutes on each side to desired doneness. Add consommé or stock to pan to deglaze.