In a small jar, add shallot, vinegar, olive oil, mustard, honey and lemon juice. Add lid and shake vigorously. Taste and season with salt and pepper. Set aside.
In a medium sauté pan on medium high heat, add olive oil and heat for 1-2 minutes. Add peaches and sauté for 6-8 minutes or until they begin to caramelize. Remove pan from heat.
Divide spinach, red onion and peaches between two dinner plates. Re-shake dressing and drizzle over each salad. Garnish with sliced almonds if desired.