Combine the water and cream in a heavy-bottomed 4-quart pan over medium-high heat. Add salt and pepper to taste and bring to a full, rolling boil. Add the grits and whisk vigorously until the water is absorbed, about 15 to 20 minutes; watch carefully so they don't dry out and burn. The grits should be smooth and creamy. Remove pan from the heat and whisk in the butter and cheeses, making sure they are well incorporated. The consistency should resemble creamy mashed potatoes.  Set aside to keep warm.

Rinse the shrimp and pat them completely dry. Coat the shrimp heavily with the seafood seasoning; set aside. Fry the diced bacon in a heavy-bottomed 12 inch cast iron skillet over medium-high heat until browned and crisp. Using a slotted spoon, remove the bacon pieces and set aside to drain. Add the onion to the pan and cook about five minutes or until onion is wilted and transparent. Toss in the garlic and shrimp and cook, stirring often, just until the shrimp turn pink and are opaque throughout. Add the lemon juice, chopped tomatoes, parsley, green onions, and reserved bacon. Saute for two to three minutes, or until ingredients are well integrated.

Spoon a portion of the hot grits into individual rimmed bowls. Spoon equal portions of the shrimp mixture over each serving and serve immediately.

Recipe courtesty of Texas On the Table by Terry Thompson Anderson:  https://amzn.to/2VpxPx6

JEN'S COMMENTARY

I like to think of recipes as "guidelines".  Frequently, I will mesh different recipes together, using the ingredients and techniques that I find most interesting or appealing.  If I don't have an ingredient on hand, I'm comfortable making substitutions.--and I'd say they work about 90% of the time.  My general rule before taking big risks with altering recipes is to always have a back up plan...ours is usually frozen pizza. 

When looking for a substitution, think about what you have on hand that can do the job of what you are missing.   

Let's start with the grits.  This one isn't easy.  If I had to substitute something, I'd pick risotto.  The ratios of the liquid are going to be different though, so I'd suggest googling Cheesy Risotto, and just be sure to include some blue cheese along with another sharp cheese.  The key is to balance out the funky flavor of the blue cheese with the fat from cream and the other cheeses. 

Butter.  Substitute with more cream or whole milk (skim or 2% will not do the job).   

Cream.  half and half would work  Whole milk would be risky but doable.  

Cheddar Cheese.  Any creamy, sharp cheese should work, and the pre-shredded stuff works just fine.  I like the 4 cheese Mexican blend.  I'd avoid bland options like mozzarella and provolone, and Swiss will likely clash with the blue.   

Blue Cheese.  This item must stay.  My favorite is buttermilk blue.

Shrimp.  I usually get the stuff that is already peeled and deveined from the seafood shop at Central Market.  Frozen can work.

Cajun Seafood seasoning.  I did not have this on hand when I last made the recipe, and instead used some BBQ rub and added just a pinch of chipotle powder.  If you aren't sure what to use, cajun seasoning usually has paprika, pepper, garlic/onion powder, chili powder, salt and  something with spice, like cayenne pepper.  Feel free to create your own seasoning to your taste.

Bacon.  This is an essential item for this recipe.  You could leave it out, but you'd miss it.  If omitted, consider adding salt to taste at the end.

Onion.  A shallot will work fine.    

Garlic.   The recipe calls for 1 clove of garlic. I used about 5.  While I prefer fresh garlic, the powder will work in a pinch.  Granulated garlic is best, but garlic powder is a good second choice.  If all you have is garlic salt, it will work but (obviously) has more salt, so be sure to taste it as you go.

Fresh lemon juice.  Lemon juice adds acid and that's what we are looking for here.  I've used limes before, and wasn't thrilled with that choice.  I'd suggest apple cider vinegar or an acidic white wine instead.

Roma Tomatoes.  Romas work great, but I also frequently use grape tomatoes.  Any sort of tomato would do.  If you only have canned tomatoes, I think chopped would work best, but even diced tomatoes will add the acidity and flavor you want.

Parsley.  Every chef in the world will disagree with me, but I rarely include parsley in anything.  I just never see it as necessary.  When cooking for my family, I don't feel the need to garnish.  I leave this one out every time.  Feel free to include any other herb you find handy or inspirational.

Green Onions.  Personally, I feel like green onions add a nice flavor and some nice aesthetics. My husband, however, has strong feelings about the smell and taste, therefore, I rarely use them.  The last time I made this, I used chopped shallots, and everyone was happy with that choice.  You could likely omit the green onion altogether in a pinch and the dish would still be delicious.