Combine all ingredients for the lemon-dill yogurt sauce in a small bowl. Stir well and refrigerate until ready to use.: The sauce should smell bright from the lemon zest and a savory herbal note from the dried dill , with a creamy tang from the plain Greek yogurt . Whisking until smooth releases the aroma of the oils in the lemon zest and helps the honey dissolve for a glossy texture. Chill tight in the refrigerator so the flavors meld and the sauce firms slightly, which makes it easier to spoon onto burgers. Common mistake to avoid is over-salting at this stage, since the patties and toppings will add sodium later.
Wash, peel, and chop 1 large (or 2 medium) beet. Place in a food processor and pulse into small rice-sized pieces. Measure out 3 cups of grated beet and save the rest for other recipes.: You will notice the beet releasing a faint earthy scent as you pulse it, and the sound will turn from loud chopping to a softer, rice-like whir. The visual cue to watch for is uniform, small pieces about the size of coarse rice, which ensures even mixing and cooking. Too-fine processing turns the beet into a puree and risks adding too much moisture, while too-coarse shreds can prevent the patties from holding. A common slip is not draining excess beet liquid, which can make the mixture too wet to shape.
Add the rice, yellow curry powder, cumin, turmeric, dill, salt, and garlic. Turn your food processor on and process until thick and sticky (you will need to stop and stir the mixture several times).: As you process, inhale the warm aroma of yellow curry powder and toasted ground cumin , a signal the spices are integrating. The texture will change from loose bits to a cohesive, tacky mass that clumps when pressed between your fingers, which is your visual and tactile sign to stop. Stirring intermittently ensures even distribution of spices throughout the beet and brown rice . A frequent error is over-processing, which makes the mixture pasty and reduces the contrast in texture that makes the patties appealing.
Add enough oil to a cast iron skillet to generously coat the surface and heat to medium.: When the pan heats, the coconut oil will shimmer and release a faint sweet smell, and you may see the oil ripple across the surface. Medium heat is key because it allows the exterior to crisp and brown without burning, while the interior gently warms and binds. A good test is to carefully flick a drop of water into the pan; it should sizzle steadily. The most common mistake is using too high a heat, which browns the outside before the interior sets, or too little heat, which results in soggy patties.
Form burger patties out of the beet/rice mixture and place on the hot cast iron skillet. Allow patties to cook 2 to 3 minutes (or until crispy). Carefully flip to the other side and allow them to cook another 2 to 3 minutes.: Listen for a confident sizzle when the patties hit the skillet; that sound means the exterior is searing and forming a crust. Visually, edges should turn a deeper color and develop small browned spots, indicating the Maillard reaction is happening, which adds savoriness. After flipping, check for a similar crispness on the second side. Use a thin spatula and gentle motion to avoid breaking the patties. A frequent mistake is turning too early; if the patty resists, give it more time to form its crust.
Serve beet burgers on lettuce of choice with lemon-dill yogurt sauce, thick slices of avocado, and sprouts.: The final plate should have contrasts of texture and temperature, cool creamy plain Greek yogurt sauce against warm, crisp-edged patties, and silky avocado next to crunchy Sprouts and crisp Butter Lettuce . Spoon the sauce generously so each bite gets a balance of tang and cream. A visual cue of a finished plate is a vibrant pop of green from the greens and avocado set against the deep magenta of the patties. Avoid piling too many toppings which can make the burger unwieldy to eat.