Add the vegetable broth and beer to a saucepan, bring to a boil then reduce to a low simmer.
Add the grits and salt, simmer, stirring occasionally until the grits have softened.
Stir in the half and half, salt, and garlic powder.
Preheat the grill to medium-high.
Brush the corn on all sides with oil, set aside.
Add the shrimp to a bowl, squeeze half of the lime over the shrimp, sprinkle with 1 tablespoon Tajin, toss to coat. Thread onto skewers.
Slice the Halloumi into ½ inch slices, sprinkle on all sides with the remaining Tajin.
Add the corn, shrimp, and Halloumi to the grill, grilling on all sides until shrimp is cooked through and grill marks appear on all.
Cut the kernels of the corn, add to a bowl along with the cilantro, and cotija, toss to combine.
Divide the polenta between 4 bowls, top with corn mixture, crema, tomatoes, shrimp skewers and Halloumi.
Notes
If you don't have Tajin, mix together 1 teaspoon salt, 2 teaspoon chili powder, 1/2 teaspoon garlic powder, 1/4 teaspoon cayenne pepper and 1/2 teaspoon cumin.