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 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.