Place a large pot or Dutch oven over medium heat. Add the ground beef and break it apart with a stiff spatula. Cook until fully browned, about 7–10 minutes, and drain excess liquid if desired. Remove the beef and set aside.
In the same pot, add achiote paste and oil. Stir until melted and colored with red. Add potatoes, carrots, garlic, onion, celery, and bell pepper. Cook for about 3–4 minutes, stirring occasionally, until the vegetables start to soften.
Pour in the marinara sauce and chicken or beef stock. Stir to combine and cook for 2 minutes.
Return the cooked ground beef to the pot. Add bay leaves, dried oregano, black pepper, cumin seeds, salt, and chili powder (optional). Stir gently to mix all the flavors.
Cover the pot and cook for about 10 minutes. Remove the lid, stir, cover again, and continue cooking. Repeat this until the picadillo has cooked for approximately 35 minutes, adjusting heat to maintain a gentle simmer. Remove the lid, taste, and adjust seasoning if needed. Continue cooking uncovered for 20–30 minutes until the sauce reduces and thickens.
Remove the bay leaves. Add chopped cilantro and stir gently before serving. Serve with warm white rice and freshly made black beans.