Step 1

Combine 2 cups potlikker and 2 cups cold water in a medium saucepan; whisk in grits. Set pan over medium heat and bring to a boil. Reduce heat to medium-low; add bay leaf and 2 tsp. Diamond Crystal or 1 tsp. Morton kosher salt. Cook, whisking often, until grits are thick and creamy, 40–45 minutes if using stone-ground grits or 20–25 minutes if using regular grits. Stir in 1 tsp. pepper and season with salt. Remove and discard bay leaf. Cover pan and keep grits warm over very low heat, whisking occasionally.

Step 2

Sprinkle shrimp with remaining 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt and remaining 1 tsp. pepper. Heat oil in a medium skillet over medium-high. Working in batches, add shrimp to skillet and cook until just opaque, about 2 minutes per side. Transfer shrimp to a plate.

Step 3

Reduce heat to medium. Add fennel stems to skillet; cook, stirring often, until starting to brown and soften, about 5 minutes. Add garlic and red pepper flakes and cook, stirring, until fragrant, about 1 minute. Add tomatoes and remaining ½ cup potlikker. Bring to a simmer and cook until tomatoes have begun to fall apart, about 5 minutes.

Step 4

Return shrimp to skillet and cook until opaque throughout, about 1 minute. Season with salt and pepper; remove skillet from heat.

Step 5

If grits have stiffened, loosen with a little more potlikker or water before dividing among bowls. Top with shrimp and sauce. Scatter fennel fronds over.