Heat a medium saucepan over medium heat, add the chicken stock and bring to a boil. Slowly whisk in the grits and reduce the heat to medium-low.
Cook the grits until tender, about 15 to 20 minutes, stirring frequently with a wooden spoon, breaking up any clumps with the back of the spoon. Remove the saucepan from the heat and stir in the butter and then the cheese until completely melted. Season with salt and pepper.
For the collard greens:
Heat a medium sauté pan over low heat and add the bacon. Turn the heat up to medium and cook until the fat renders and the bacon is crispy. Remove to a paper towel lined plate using a slotted spoon.
Leave as much of the bacon fat in the pan as possible then add the onion and garlic and sauté until tender, about 6 minutes. Add the collard greens and sauté until they are wilted, about 4 minutes.
Add the chicken stock and continue to cook, until the greens are tender, about 6 additional minutes. Season with salt and pepper and top with the bacon. If the liquid absorbs too fast, add more 1/4 cup at a time.
For the shrimp:
Heat a large sauté pan over medium heat, add the olive oil and heat through. Add the butter and allow to melt.
In a small bowl stir together the paprika, garlic powder, onion powder, oregano, thyme, cayenne and pepper. Season the shrimp on both sides with the Cajun seasoning mix.
Arrange the shrimp in the pan and sauté on both sides until pink and no longer translucent, about 1 minute per side. Remove the shrimp from the pan and set aside.
To serve:
Ladle the grits into warmed bowls then top with collard greens, sliced heirloom tomatoes and the Cajun shrimp. Garnish with parsley.