Lamb:
Preheat the oven to 350 degrees F.
Season the lamb generously with salt and pepper on both sides. Season with garlic powder, cumin, coriander and chili powder on both sides. Rub all the spices into the meat.
Heat the grapeseed oil in a large dutch oven over medium high heat. Add the lamb to the dutch oven and brown on both sides, 3-4 minutes.
Add the beer, honey, vinegar and hot sauce or pepper to the pot. Bring the liquid to a simmer, cover and cook in the oven for two hours or until the lamb is very tender.
Once the lamb is cooked, shred the meat and toss it with any excess liquid.
Chive Tzatziki:
Add the peeled and diced cucumbers to a colander and sprinkle with salt to draw the water out. Let the cucumbers sit for 30 minutes, drain and squeeze them dry with a paper towel to get rid of any excess moisture.
In a food processor or blender, add the cucumbers, lime juice, garlic, and chives. Process until well blended. Stir in yogurt and season to taste with salt and pepper. Garnish with more chives. Keep cool until serving time.
Radish Salsa:
Mix all the ingredients together in a medium bowl. Keep cool until serving time.
To Assemble:
Warm the tortillas. Fill each tortilla with lamb meat and top with salsa and tzatziki sauce. Garnish with cilantro, chives and a squeeze of lime, if desired.