• Heat a small skillet over medium heat. Add the cumin seeds and coriander seeds. Toast, stirring and shaking the skillet often,for 2-3 minutes. The seeds will deepen in color and become highly aromatic. Remove from heat, allow to cool slightly, and grind to a powder in a spice grinder or mortar and pestle.
• Strain and pat out any excess moisture from the ground beef and place into a large bowl or bowl of a stand mixer. The kebab mixture should be as dry as possible to prevent any breaking.
• Add the onion, cilantro, mint, and green chili peppers to a food processor. Using the pulse function, finely chop (but not blend) them to a coarse mixture (~17 pulses). You may need to pause and scrape down the sides in between. Remove the onion mixture, squeeze out the excess moisture between your hands, and add to the beef.
• Add the salt, garlic, ginger, black pepper, red chili flakes, garam masala, toasted & ground cumin & coriander, and papaya paste (if using). Mix well.
• Using gloved hands (do not use bare hands or the green chili may sting), knead for 3-4 minutes, until you begin to see a lacy, stringy texture (resha) of the meat. (Alternatively, you can use the paddle attachment of a food processor and knead on medium speed for 2 minutes.) The mixture should be homogenous instead of crumbly.
• Cover the bowl and set aside for 30 minutes, or refrigerate up to overnight.
• To test a piece for taste, heat a small pan over medium-high heat. Add a small amount of neutral oil and place a piece of the beef mixture on the pan to cook, turning over as needed. Taste and adjust salt and seasoning if desired.
• Using oiled hands, take around 1/4 cup of themeat and form into a hearty round shape. Run the kebab skewers through the meat and use your hands to form a sausage-like shape around the skewer. It should come to 5-6 inches long. (See Note on how to freeze.)

For Pan-Frying:

• Heat a large, nonstick or cast iron skillet over medium or medium-high heat. Add enough oil to coat the bottom of the pan. When the oil is hot, place the kebabs on the pan, making sure not to crowd them. Use tongs to turn the kebabs frequently, making sure all sides are browned evenly. Cook for 6-7 minutes in total. If you have a meat thermometer, it should read at least 160 °F. Transfer the kebabs to a large plate lined with a paper towel.

For Air-Frying:

• Place the kebabs in a single layer leaving room on both sides. Cook at 400 °F for 4-5 min. Then turn and cook for another 3-4 minutes, until browned and cooked through.

For Baking:

• Preheat the oven to 430°F/220°C. Place one rack in the middle of the oven, and the other rack at top so that your sheet pan can be as close as possible to the heat source/broiler. Place the kebabs on a baking sheet lined with aluminum foil. Brush with oil or butter, if desired. Bake in the middle rack for 8-10 minutes, turning them over midway. Transfer the pan to the top rack.
• Turn your broiler on High (550°F/287°C). Broil for 2 minutes. Then turn and broil for another 1-2 minutes. (See Note 2)

To Serve

• Serve immediately with cilantro mint raita/chutney, crunchy vegetables, and lemon wedges.