Halve each passion fruit, scrape flesh into a strainer, and push through with a rubber spatula to yield 3 tablespoons juice. Set aside.
Season salmon with salt and pepper. Heat oil in a nonstick skillet over medium-high heat; add salmon and cook about 4 minutes per side, until just cooked through. Transfer to a plate; cover with foil.
Return skillet to low heat; add 1/2 tablespoon butter and shallots; cook, stirring, until golden, 1 to 2 minutes. Add reserved juice, mustard, honey, vinegar, and wine. Raise heat to high; cook until thickened, 1 to 2 minutes. Remove from heat; swirl in remaining butter.
Divide greens and sauteed spring vegetables among plates; place salmon on top and drizzle sauce over salmon.