Toast the pepper, coriander and cumin together in a dry pan over low heat until they crackle and pop (shake the pan constantly). Their color should be light brown, and spices should smell like toast, popcorn, smoky, etc. Pour them straight into a coffee grinder and blend the seeds to a fine powder. Add the lamb to a medium bowl and stir in all of the spices, the garlic and salt. Combine well. Form the lamb mixture into 6 even patties.
Open the dried peppers and shake out the seeds (a few seeds left in is ok). Add the peppers to a saucepan with the water, and boil over medium heat until only 1/4 cup of liquid remains at the bottom. Add the peppers (with cooking liquid), sour cream, oil, garlic and lime to a blender, and blend it until very smooth. Add the salt and blend again. Pour in enough cream to thin the mixture to a saucy consistency. Pulse a few times to incorporate and get squirtable consistency.
Grill the lamb patties and the ciabatta until nice, dark grill marks are everywhere (lamb is at its juiciest around medium-rare). Put about 1 teaspoon of the sauce on each side of the bun. Slice the patties in half to lay lengthwise on the bread. Crumble the Cotija cheese over the top. Dress Add the onion, tomato slices and lettuce. Cut sandwich lengthwise (along the seam of the lamb patty) and plate with the cross-section facing outward.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Michael Sohocki at The Cove in San Antonio, TX