In a bowl, combine the shrimp with the tomato paste, harissa, garlic, cilantro, and a drizzle of olive oil. Season with salt and pepper. Toss until the shrimp are well coated and let marinate for a few minutes.
In a separate bowl, combine the mayonnaise, mustard, a little cilantro, a splash of white balsamic vinegar, and the lime juice. Season with salt and pepper to taste. Refrigerate until ready to serve.
Preheat the grill to medium-high heat. Place the ears of corn directly on the grill and cook for a few minutes on each side, until nicely charred and lightly blackened in spots. Remove the corn kernels from the cobs using a knife.
Thread the shrimp onto skewers to make them easier to grill. Cook for about 2–3 minutes per side, until fully cooked and lightly charred.
If you don’t have a grill, cook the shrimp in a hot skillet for about 2–3 minutes per side.
Lightly warm the tortillas on the grill or in a skillet. Top each tortilla with a little creamy sauce, grilled shrimp, and grilled corn. Finish with crumbled feta and a few cilantro leaves.
