Chop about 3/4 cups worth of leaves and flowers only of the broccoli rabe into very small pieces and set aside for the burger.: The moment you begin chopping you will notice a bright, herbaceous smell from the broccoli rabe . Finely chopping the leaves and flowers releases their fresh oils, which helps them meld into the turkey and keep the patties moist. If your pieces are too large the texture will be uneven, so aim for small, consistent pieces. Avoid overloading the mix with stems here, they are tougher and belong in the sauté step later.
Cut the remaining broccoli rabe into 2-inch pieces.: After reserving the leafy tops, cut the remaining stalks into uniform two inch lengths so they blanch evenly. When you cut them you should see a firm, slightly fibrous interior. Uniform pieces ensure consistent cooking during the blanch and sauté. A common mistake is leaving very long stems which will stay tough after cooking, so trim them carefully.
Bring a large pot of salted water to a rolling boil, then add the broccoli rabe.: The pot should be at a true rolling boil before adding the greens, which helps them cook quickly and retain color. You will hear the water rumble and see active movement when it is ready. Use enough salt so the water tastes like the sea, this seasons the broccoli rabe internally. Do not add the greens to lukewarm water, they will become limp and bland.
Blanch for about 1-1/2 to 2 minutes, drain well and set aside in a colander.: The brief blanch should leave the greens bright green and slightly tender to the bite. You'll see the color intensify, and a quick drain in a colander removes excess water that could make patties soggy. After blanching, press gently to shed remaining liquid. Overcooking here results in a dull, mushy texture so watch the clock closely.
Meanwhile, in a medium bowl, combine the turkey, 3/4 cup chopped broccoli rabe, Romano cheese, garlic, salt and pepper (red pepper flakes too if using).: When you mix these components the air will lift the aroma of Pecorino Romano cheese and garlic , signaling the flavor foundation. Use a gentle folding motion to distribute the chopped broccoli rabe evenly without overworking the turkey , which can make the patties dense. If you overmix, the burgers may firm up and lose juiciness, so combine until just even.
Form into 4 patties and refrigerate until ready to cook.: As you form each patty, press just enough to hold the shape, about three quarters to one inch thick. Chilling helps them firm up so they hold together on the skillet. You will notice they become easier to sear after refrigeration. A common error is making patties too thin which causes them to dry out quickly during cooking.
Heat a large, deep sauté pan to medium-high heat, when hot add the olive oil and garlic and cook until golden about 1 minute, careful not to burn.: When the pan is hot you will hear a faint sizzle as the olive oil meets the surface, and the garlic will become aromatic and turn a pale golden color. That toasty scent is what you want, but watch closely since garlic can go from golden to bitter quickly. If the garlic burns you will taste that acrid note in the greens, so reduce heat immediately if it darkens too fast.
Add the broccoli rabe to the pan and toss with garlic and oil, season with 1/4 tsp salt and crushed red pepper; cook about 2 to 3 minutes, or until heated through.: Tossing the blanched pieces in the sizzling oil allows the flavors to bloom and the edges to blister slightly, producing a pleasant wilted crispness. You will see a glossy coating on the greens and smell a nutty, garlicky fragrance. Cooking them just to heated through preserves color and texture; overcooking will make them limp and muddy tasting.
While that is cooking, cook the burgers on a hot skillet over medium-high heat for about 6 to 7 minutes on each side, or until cooked through in the center.: As the patties sear you will hear a steady sizzle and notice a golden brown crust form, sealing juices inside. The aroma of browned meat combined with the cheese will be inviting. Flip only once if possible to preserve the crust. Use an instant read thermometer when in doubt, the center should register a safe temperature for turkey . Avoid pressing down on the patties, which squeezes out juices and dries them.
To serve place a lettuce leave on each plate, top tomato slice and cooked burger.: The cool lettuce and juicy tomato provide fresh temperature contrast to the hot burger, and the acidity from the tomato brightens the palate. Arrange the components so the burger stays warm but the veggies keep their crispness. Serving directly on a bun will work too, but this simple assembly emphasizes the clean flavors.
Finish with the cooked broccoli rabe and optional more grated cheese if desired.: The final layer of sautéed broccoli rabe brings an herbaceous, slightly bitter finish that complements the savory patty. A sprinkling of additional Pecorino Romano cheese adds a salty flourish. Taste once more and adjust salt if needed, and avoid adding too much cheese which can mask the green notes.