Preheat the oven to 350º. In a large bowl, whisk together the flour, salt, pepper and cumin. Toss the pork shoulder in the flour to dredge, shaking off any excess flour.
In a 6-quart Dutch oven, heat 1½ tablespoons of the lard and 2 tablespoons of the olive oil over medium heat. Working in 2 batches, sear the pork, turning as needed until golden brown, 7 to 10 minutes per batch. Watch the pork carefully to make sure any excess flour in the pan doesn't burn. Once seared, transfer to a plate lined with paper towels.
To the pot, add the remaining lard, the garlic and onions. Cook until translucent, 2 to 3 minutes. Return the pork to the pan with the water, oregano, cumin seeds and bay leaves. Bring to a boil, then reduce to a very low simmer and cook, covered, over low heat until the pork is tender, 2 hours.
Meanwhile, on a baking sheet toss the corn with the remaining 1 tablespoon of olive oil. Bake until golden brown, 12 to 14 minutes, then set aside.
Once the pork has simmered for 2 hours, add the roasted corn, tomatillos, hominy, roasted red peppers and jalapeño. Return to a low simmer and cook, covered, until the pork begins to fall apart, 1 hour more.
Using 2 forks, shred the pork into bite-sized pieces. Ladle the posole into bowls and garnish with the cotija cheese and cilantro leaves, then serve.