Pat the shrimp dry with paper towels. In a medium bowl toss shrimp with blackening seasoning, olive oil, and lime juice until evenly coated. Let sit 5 minutes to absorb flavors.

Cook shrimp

Heat a large cast-iron skillet or heavy-bottomed pan over medium-high heat until smoking lightly. Add the seasoned shrimp in a single layer (work in two batches if necessary). Cook 1-1.5 minutes per side until opaque and nicely charred. Remove shrimp to a plate and roughly chop into bite-sized pieces. Reserve pan drippings for flavor.

Queso base

Sauté aromatics

Wipe the skillet used for shrimp (leave browned bits). Reduce heat to medium and add butter. Once melted, add diced onion and jalapeño and sauté 4–6 minutes until softened and translucent. Add minced garlic and cook 30 seconds until fragrant.

Make roux

Sprinkle the flour over the aromatics and stir constantly for 1 minute to cook the raw flour taste.

Add dairy

Slowly whisk in the whole milk and half-and-half, scraping any browned bits from the pan. Bring the mixture to a gentle simmer for 2–3 minutes, stirring, until it begins to thicken slightly.

Incorporate cheeses & tomatoes

Reduce heat to low. Add softened cream cheese in pieces and whisk until smooth. Gradually stir in the grated cheddar and monterey jack a handful at a time, stirring until fully melted and the sauce is smooth. Stir in the drained diced tomatoes with green chiles.

Season queso

Stir in ground cumin, smoked paprika, kosher salt, and black pepper. Taste and adjust seasoning as needed. If the queso seems too thick, thin with up to 2 tablespoons of milk at a time until desired consistency is reached.

Combine shrimp with queso

Fold the chopped blackened shrimp into the queso, reserving a few pieces for garnish. Warm through on low for 1–2 minutes so the shrimp reheats but doesn't overcook.

Finishing & serving

Transfer the dip to a warm serving bowl or small cast-iron skillet. Top with reserved shrimp pieces. Sprinkle chopped cilantro, sliced green onions, and a light dusting of extra blackening seasoning if using.

Serve immediately with tortilla chips or toasted baguette slices and lime wedges alongside for squeezing over the dip.