Heat a large skillet over high heat and add 1 tablespoon of butter. Once melted, add the shrimp (no need to arrange in a single layer), along with a pinch of cayenne pepper and salt.
Sauté for about 2 minutes, stirring occasionally, just until the shrimp are about 75% cooked. Transfer the shrimp and any released juices to a bowl and set aside.
Reduce the heat to medium and add the remaining butter to the skillet, and let it melt.
Add the cumin seeds and let them sizzle for about 10 seconds until fragrant. Stir in the chopped onion, garlic, ginger, and a pinch of salt. Cook, stirring frequently, until the onions turn golden brown and caramelized, about 4 to 5 minutes.
Add the kasoori methi, coriander powder, garam masala, the remaining cayenne, and about 2 tablespoons of water.
Cook for 2 to 3 minutes, stirring constantly, until the spices are well-toasted and aromatic. The splash of water helps prevent the spices from burning.
Stir in the tomato sauce, cashew powder, and ¼ cup of water until well combined. Reduce the heat to low, cover the pan, and let it simmer for about 10 minutes, stirring every 3 to 4 minutes to prevent the sauce from sticking or burning at the bottom.
Uncover the pan and stir in the cooked shrimp along with any accumulated juices, followed by the heavy cream, honey, orange food coloring (if using), and the remaining salt. Let the sauce simmer gently for about 2 minutes, just until the shrimp are fully cooked and the flavors meld together.
Remove from heat and let rest for few minutes before serving. Delicious served with naan and/or rice.