In a large skillet over medium-high heat, add the fresh corn kernels and cook until charred, around 5 minutes. Remove from pan and place in a large bowl. Add remaining chimichurri ingredients and toss gently to combine. Set aside.
In a small bowl, whisk together the sour cream, lime zest, lime juice, salt, and pepper. Add water, 1 tsp. at a time, until crema reaches a drizzling consistency. Set aside.
In same skillet the corn was cooked in, add 1/2 tbsp. of olive oil and heat to medium-high. When olive oil is shimmering, add the poblano pepper and cook until slightly tender, around 3 minutes. Add the shallot and continue to cook for another 2-3 minutes, or until softened and lightly browned. Season with salt and pepper, then remove from pan and set aside.
Heat another 1/2 tbsp. of olive in the pan, then add the pork and cook, breaking the meat up as it cooks, until no longer pink, around 5 minutes. Add garlic and cook for 1 minute, then season with salt and pepper. Stir in the cooked poblano peppers and shallot, then add the tomato paste, stock concentrate, cumin, and water. Stir to combine and allow to thicken for 2-3 minutes. Adjust seasoning as desired.
Scoop pork mixture into warmed tortillas, then top with corn chimichurri. Drizzle with lime crema and sprinkle with cotija and enjoy!