1 lb. sugar snap peas, strings removed, cut in half on the diagonal
6 radishes, ends trimmed, halved and thinly sliced
3 baby or pickling cucumbers, well scrubbed, unpeeled and cut into 1/4-inch thick slices
2 pink or white grapefruit
1/3 cup tightly packed mint leaves
3 Tbsp. extra-virgin olive oil
1 Tbsp. minced shallot
1 Tbsp. fresh lemon juice
1 Tbsp. rice vinegar
1/2 tsp. kosher salt, or to taste
1/4 tsp. freshly ground black pepper