
Place the chicken into a large bowl, and toss with 1/4 tsp each of salt and pepper, and flour. Make sure strips are coated evenly.
Heat a large skillet over medium high heat. Add the 2 tsp of butter, along with 1 tbsp olive oil and sauté the chicken strips till golden brown, about 3-4 minutes per side, turning when needed. Transfer to a plate. Use a piece of paper towel to wipe out the pan of any bits that could scorch during the next step.
Increase the heat to medium-high, heat 2 tablespoons (30 ml) olive oil over high heat until shimmering. Add the shrimp in an even layer and cook, stirring and turning shrimp occasionally, until just cooked through, and just starting to turn golden in spots, about 2-3 minutes. Using a slotted spoon, or tongs, transfer shrimp to the plate with the chicken. Repeat with remaining shrimp if they didn't all fit in one batch, adding more oil if necessary.
Add the remaining 1 tablespoon (15ml) olive oil to skillet, along with garlic and red pepper flakes. Cook, stirring constantly to keep the garlic moving, until it is just starting to turn golden, about 45 seconds or so; lower heat if necessary to prevent scorching.
Reduce the heat back to medium high. Add the cubed butter and cook, stirring and swirling pan rapidly as butter melts to create a silky, emulsified sauce. Remove from heat, add lemon juice, and season with salt. Reduce to medium heat and bring to a simmer, constantly stirring the lemon juice into the butter sauce. (If sauce breaks apart, whisk in a teaspoon or two of water until sauce emulsifies again.) Taste the sauce to see if it needs more salt.
Feel free to use all chicken or all shrimp. Just double and cook as directed.
This dish can be served at room temperature as a salad of sorts, just use an easier to manage pasta like rigatoni, macaroni, or orzo.