Preheat the broiler to high. Place the rolls on a broiler pan and toast until golden. Rub with the garlic and drizzle with oil.
In a medium bowl, combine the beef with the Worcestershire sauce, sage, shallot, and parsley; season with salt and pepper. Divide into 4 equal pieces and form 3 sliders from each piece. 12 mini sliders total.
Heat a large skillet over medium-high heat with a drizzle of oil. Cook the sliders for 3 minutes on the first side and 1 to 2 minutes on the other side for medium.
Top each bun bottom with some spinach, a slider, and a few cheese crumbles. Place under the broiler to melt the cheese a bit, about 30 seconds, then set the bun tops in place.
