To make dressing place garlic, mint and lemon zest into Thermomix bowl and mill 4 sec/speed 8.
Add remaining ingredients and blend 1 min/speed 4-5 until smooth and creamy. Set aside.
Prepare capsicums by deseeding and cutting into strips. Drizzle with EVOO and season with salt flakes. Place the red onions onto the same tray and drizzle with EVOO and vinegar, the sugar and salt to taste. Roast in the oven with a grill function on 200°C until well softened and caramelised. Cool slightly. (approx 20 minutes, but keep an eye on them.)
Cook lamb on hot grill pan on a very high heat until cooked to your liking. Rest lamb, wrapped in foil until ready to serve. While pan is still hot, quickly charr the snow peas.
Place greens onto your serving platter, arrange capsicum strips, grilled onion and cucumber over.
Slice the lamb, and add it and the charred snow peas to the salad. Crumble more feta over, drizzle with dressing and garnish with additional mint leaves. Serve!
Serve immediately.