Fill a medium saucepan with a lid with 1/2-inch of water and bring it to a boil over medium-high heat. Add the cauliflower; reduce the heat to medium, cover, and steam until tender when pierced with a fork, 6 to 8 minutes. Drain well, transfer the cauliflower to a cutting board to cool, then finely chop the cauliflower into small pieces. Set aside.
Pour the half and half into a saucepan with 2 tablespoons of the coconut flour and the butter. Turn the heat to medium-high and slowly bring the mixture to a boil, whisking constantly until smooth and thick, 3 to 4 minutes. Add the chopped cauliflower, Manchego cheese, ham, and 1/2 teaspoons salt and 1/8 teaspoon pepper. Let cool in the pan.
Line a rimmed baking sheet with plastic wrap. Spread the creamy cauliflower mixture evenly onto the prepared baking sheet. Cover with plastic wrap, pressing it onto the surface of the mixture to eliminate air bubbles. Refrigerate for 1 hour or overnight.
Place the remaining 6 tablespoons coconut flour in a shallow bowl. Mix in 3/4 teaspoon salt and 1/4 teaspoon pepper.
In another shallow bowl, whisk together the eggs and 2 tablespoons water.
In a third shallow bowl, combine the pork rinds and Parmesan cheese.
Unwrap the cauliflower mixture. Cut the cauliflower mixture into 24 even pieces. Place a small drop of oil on your hands to lightly grease them. Working one at a time, roll each piece of the cauliflower mixture into a small, tightly packed oval, then dredge it in the flour mixture, tossing to coat. Next, dip it in the egg, shaking off any excess, then gently toss it in the pork rind-parmesan crumbs. Gently shake off excess crumbs and place each coated croquetta on a clean sheet pan.
Set aside a wire rack on a sheet pan.
In a medium skillet, heat 1 cup olive oil to 365°F (185°C). Gently place 6 to 8 croquettas at a time to avoid overcrowding and fry until they’re golden brown all over, or 2 minutes per side. Use a slotted spoon to transfer them to the prepared wire rack.
Meanwhile, make the crèma: In a medium bowl, whisk together the sour cream, smoked paprika, lemon juice, 1/2 teaspoon salt, and 1/8 teaspoon pepper. Transfer the crèma to a serving bowl.
Arrange the croquettas on a serving plate/platter and serve with the crèma.