In a medium saucepan, bring chicken broth to a boil over high heat. Gradually whisk in grits, reduce heat to low and cook, whisking, until very thick, approximately 4 1/2 minutes. Whisk in cheese and scallions until well combined. Taste and season with salt, if desired. Remove from heat and cover to keep warm.
In a medium skillet, warm olive oil over medium-high heat. Add shrimp, season with salt and cook, stirring, until almost pink, approximately 2 minutes. Stir in lemon juice, garlic and peas, then continue to cook, stirring, until shrimp are cooked through, 2 to 3 minutes longer.
Divide grits among 4 bowls. Top with shrimp mixture, then serve immediately.
