Preheat the oven to 400°F and place a rack in the middle. Line a rimmed baking sheet with foil or parchment.

Add all of the meatball ingredients in a large bowl and, using your fingers or a fork, gently mix everything together until fully combined. Don’t squeeze the meat or the meatballs will be tough. Form the mixture into 2-inch meatballs (a scoop is great though you can also just estimate) and arrange them on the baking sheet with a little space between each ball. Bake the meatballs until golden brown and just cooked through, about 12 to 14 minutes. Remove the tray from the oven and set them aside.

While the meatballs are cooking, make the curry sauce. Heat the oil on medium-high in a deep, wide skillet or dutch oven. Add the onion and cook, stirrinq often, until the onion turns soft and translucent, about 5 to 7 minutes. Stir in the garlic and ginger and cook until fragrant, about 1 minute. Add the red curry paste and cook, stirring everything around, until the paste sizzles and turns a darker red, about 3 minutes. Stir in the coconut milk, chicken stock, fish sauce, sugar and peanut butter and bring sauce to a boil, then lower the heat and gently simmer until the sauce thickens slightly, about 5 minutes. Add in the spinach and lime juice and stir until wilted, 1 minute. Transfer the meatballs to the sauce and gently toss until coated in sauce.

Serve on top of rice or rice noodles, with lots of fresh herbs and lime wedges for squeezing.