In a medium bowl, add the shrimp, lavender and 1/2 teaspoon salt and toss well to combine. Heat a large skillet over medium-high heat. Add the oil and the seasoned shrimp and cook, undisturbed, about 2 minutes. Flip the shrimp and cook on the other side until the shrimp is opaque and cooked through, about another 2 minutes.
In a separate medium bowl, add the mint, lemon zest and juice, oranges and zest, cucumbers and 1/8 teaspoon salt. Toss well to combine. Add the hot shrimp to the bowl and toss again.
Lay the endive leaves out on a platter. Spoon the shrimp mixture into the leaves, placing approximately 2 shrimp in each cup. Spoon any juices over the top and serve.