"I was at the store looking for something tasty for dinner and came across some lamb shanks. Reading the cooking instructions gave me an idea for some awesome sliders. I grabbed some ingredients and threw this together. The result was a mouth-watering, spicy surprise! Add spices of your own to suit your taste. When you're done, take a bite and wipe your face with a paper towel."
Place lamb shanks into a slow cooker; add water. Stir stem side of the halved jalapeno to the slow cooker, reserving the other end.
Set slow cooker to High; cook until lamb is tender and can be easily pulled apart with a fork, 1 to 2 hours. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).
Preheat oven to 375 degrees F (190 degrees C). Place ciabatta rolls onto a baking sheet.
Bake in the preheated oven until crisp and browned, 10 to 15 minutes.
Remove jalapeno half from the slow cooker; dice, along with the reserved half.
Heat oil in a skillet over medium-high heat. Stir in bell peppers, onion, diced jalapeno, salt, and pepper; cook and stir until bell peppers are tender and onion is translucent, 7 to 10 minutes.
Combine mayonnaise and chile-garlic sauce in a small bowl; stir until sauce is mixed.
Remove lamb from the slow cooker. Separate lamb meat from the bone; discard bones. Shred lamb with a fork; divide into 8 equal portions.
Spread sauce onto the top half of the ciabatta; cover with spinach leaves. Spoon lamb and vegetable mixture onto the bottom half of the ciabatta; top with sliced jalapeno.