Step 1

Finely grate the zest of 1 lime into a bowl. Add coriander, cumin, cayenne and 2 tablespoons oil and mix to combine. Transfer half to a medium bowl and toss with shrimp. In a second bowl, toss chicken with remaining mixture.

Step 2

Thread each protein onto its own skewer. Halve all limes.

Step 3

Toss peppers, jalapeños and onions with remaining 2 tablespoons oil and 1/2 teaspoon each salt and pepper. Thread jalapeños, peppers and onions onto their own skewers.

Step 4

Heat grill to medium-high. Season chicken and shrimp skewers with 1/2 teaspoon each salt and pepper.

Step 5

Add skewers to grill and cook, turning occasionally, until chicken is cooked through (8 to 10 minutes), vegetables are just tender (4 to 8 minutes) and shrimp is opaque throughout (3 to 4 minutes). Transfer skewers to platter as they finish cooking. Grill limes, cut sides down, and tortillas until lightly charred, about 1 minute.

Step 6

Squeeze 1 grilled lime half over chicken and shrimp. Serve with vegetables, tortillas, remaining limes, sour cream, radishes and cilantro.